Remote delivery of a weight management intervention for adults with intellectual disabilities: Results from a randomized non-inferiority trial

BACKGROUND

Remote delivery of multi-component weight management interventions results in clinically meaningful weight loss in adults without intellectual disabilities (ID), but the effectiveness of remotely delivered weight management interventions in adults with ID has not previously been evaluated.

OBJECTIVE

To determine if a weight management intervention delivered remotely could achieve weight loss (kg) at 6 months that is non-inferior to in-person visits in adults with ID and overweight or obesity (BMI ≥25 kg/m2).

METHODS

Participants were randomized to a 24-mo. trial (6 mos weight loss,12 mos weight maintenance, 6 mos. no-contact follow up) to compare weight loss achieved with the same multicomponent intervention delivered to individual participants in their home either remotely (RD) or during face-to-face home visits (FTF).

RESULTS

One hundred twenty adults with ID (∼32 years of age, 53 % females) were randomized to the RD (n = 60) or the FTF arm (n = 60). Six-month weight loss in the RD arm (-4.9 ± 7.8 kg) was superior to 6-month weight loss achieved in the FTF arm (-2.1 ± 6.7 kg, p = 0.047). However, this may be partially attributed to the COVID-19 pandemic, since weight loss in the FTF arm was greater in participants who completed the intervention entirely pre-COVID (n = 33,-3.2 %) compared to post-COVID (n = 22, -0.61 %). Weight loss across did not differ significantly between intervention arms at 18 (p = 0.33) or 24 months (p = 0.34).

CONCLUSION

Our results suggest that remote delivery is a viable option for achieving clinically relevant weight loss and maintenance in adults with ID.

NCT REGISTRATION

NCT03291509.

Weight management for adolescents with intellectual and developmental disabilities: Rationale and design for an 18month randomized trial

Adolescents with intellectual and developmental disabilities (IDD) are an underserved group in need of weight management. However, information regarding effective weight management for this group is limited, and is based primarily on results from small, non-powered, non-randomized trials that were not conducted in accordance with current weight management guidelines. Additionally, the comparative effectiveness of emerging dietary approaches, such as portion-controlled meals (PCMs) or program delivery strategies such as video chat using tablet computers have not been evaluated. Therefore, we will conduct an 18month trial to compare weight loss (6months) and maintenance (7-18months) in 123 overweight/obese adolescents with mild to moderate IDD, and a parent, randomized to a weight management intervention delivered remotely using FaceTime™ on an iPad using either a conventional meal plan diet (RD/CD) or a Stop Light diet enhanced with PCMs (RD/eSLD), or conventional diet delivered during face-to-face home visits (FTF/CD). This design will provide an adequately powered comparison of both diet (CD vs. eSLD) and delivery strategy (FTF vs. RD). Exploratory analyses will examine the influence of behavioral session attendance, compliance with recommendations for diet (energy intake), physical activity (min/day), self-monitoring of diet and physical activity, medications, and parental variables including diet quality, physical activity, baseline weight, weight change, and beliefs and attitudes regarding diet and physical activity on both weight loss and maintenance. We will also complete a cost and contingent valuation analysis to compare costs between RD and FTF delivery.

A virtual reality intervention (Second Life) to improve weight maintenance: Rationale and design for an 18-month randomized trial

Despite the plethora of weight loss programs available in the US, the prevalence of overweight and obesity (BMI≥25kg/m(2)) among US adults continues to rise at least, in part, due to the high probability of weight regain following weight loss. Thus, the development and evaluation of novel interventions designed to improve weight maintenance are clearly needed. Virtual reality environments offer a promising platform for delivering weight maintenance interventions as they provide rapid feedback, learner experimentation, real-time personalized task selection and exploration. Utilizing virtual reality during weight maintenance allows individuals to engage in repeated experiential learning, practice skills, and participate in real-life scenarios without real-life repercussions, which may diminish weight regain. We will conduct an 18-month effectiveness trial (6 months weight loss, 12 months weight maintenance) in 202 overweight/obese adults (BMI 25-44.9kg/m(2)). Participants who achieve ≥5% weight loss following a 6month weight loss intervention delivered by phone conference call will be randomized to weight maintenance interventions delivered by conference call or conducted in a virtual environment (Second Life®). The primary aim of the study is to compare weight change during maintenance between the phone conference call and virtual groups. Secondarily, potential mediators of weight change including energy and macronutrient intake, physical activity, consumption of fruits and vegetables, self-efficacy for both physical activity and diet, and attendance and completion of experiential learning assignments will also be assessed.

Weight management for individuals with intellectual and developmental disabilities: rationale and design for an 18 month randomized trial

Weight management for individuals with intellectual and developmental disabilities (IDD) has received limited attention. Studies on weight management in this population have been conducted over short time frames, in small samples with inadequate statistical power, infrequently used a randomized design, and have not evaluated the use of emerging effective dietary strategies such as pre-packaged meals (PMs). Low energy/fat PMs may be useful in individuals with IDD as they simplify meal planning, limit undesirable food choices, teach appropriate portion sizes, are convenient and easy to prepare, and when combined with fruits and vegetables provide a high volume, low energy dense meal. A randomized effectiveness trial will be conducted in 150 overweight/obese adults with mild to moderate IDD, and their study partners to compare weight loss (6 months) and weight maintenance (12 months) between 2 weight management approaches: 1. A Stop Light Diet enhanced with reduced energy/fat PMs (eSLD); and 2. A recommended care reduced energy/fat meal plan diet (RC). The primary aim is to compare weight loss (0-6 months) and weight maintenance (7-18 months) between the eSLD and RC diets. Secondarily, changes in chronic disease risk factors between the eSLD and RC diets including blood pressure, glucose, insulin, LDL-cholesterol, and HDL-cholesterol will be compared during both weight loss and weight maintenance. Finally, potential mediators of weight loss including energy intake, physical activity, data recording, adherence to the diet, study partner self-efficacy and daily stress related to dietary change will be explored.

Is symptom relief associated with reduction in gastric retention after gastric electrical stimulation treatment in patients with gastroparesis? A sensitivity analysis with logistic regression models

BACKGROUND

Enterra gastric electrical stimulation (GES) is an alternative treatment for gastroparesis (GP) when standard medical therapy fails. The aims of this study were to evaluate the association between total symptom score (TSS) and reduction in gastric retention (GR) after GES by GP etiology and to examine the sensitivity of the association to varying cutpoints used to define GR and TSS improvement.

METHODS

Gastric retention assessed with a standardized (99m) Tc radio-labeled egg meal and TSS measured by a five-point Likert scale in 221 GP patients treated with Enterra GES therapy for at least 1 year were analyzed. Bivariate chi-square test and multivariable logistic regression with all possible cutpoints were used to assess the consistency of association and quantitate the relationship across three GP etiologies.

KEY RESULTS

Symptom relief in diabetic GP was more likely attributable to GR reduction as indicated by the consistently significant odds ratios (P < 0.01) across all cutpoints. The association in idiopathic GP was inconclusive because odds ratios were sensitive to cutpoints with P-values ranging from 0.01 to 0.47. No association was found for patients with post surgical gastroparesis (P > 0.1 for all cutpoints). Patient age, gender, baseline TSS and baseline GR had no significant effect at 5% level on clinical improvement regardless of cutpoints for GR.

CONCLUSIONS & INFERENCES

Association between clinical improvements and GR reduction following GES treatment depends on patient etiology and was able to be demonstrated in diabetic GP. The association for idiopathic GP was inconclusive and no such association was found for post surgical GP across all possible cutpoint combinations.

Perceived Treatment Assignment and Smoking Cessation in a Clinical Trial of Bupropion

Research on tobacco cessation pharmacotherapy often relies on double-blind, placebo-controlled randomized trials. These studies are designed to control for the placebo effect (i.e., the influence of participants' expectations on treatment outcome). Psychoactive effects of smoking cessation medications such as bupropion may allow participants to correctly guess their treatment assignment at rates greater than chance. Perceived treatment assignment could potentially impact smoking cessation rates. The aim of this study was to determine the impact of perceived treatment assignment on end-of-treatment cotinine-verified smoking abstinence among African-American light smokers [≤10 cigarettes per day (cpd)] enrolled in a double-blind, placebo-controlled study of bupropion. Participants were randomized to bupropion (150 mg bid) or placebo and received identical written materials and health education counseling. Participants (n = 390) included in this study reported their perceived treatment assignment on the end-of-treatment (week 7) survey. They were predominantly female (63.1%), 48.1 years (SD = 11.2), and smoked 8 cpd (SD = 2.5). The majority (81.3%) smoked menthol cigarettes. Participants given bupropion were more likely to correctly guess their treatment assignment (69%; 140/203) than those assigned to placebo (51.3%; 96/187). Quit rates by treatment assignment were 31.5% (bupropion) versus 13.9% (placebo) (OR = 2.78, 95% CI 1.61–5.43, P &lt; 0.01). After adjusting for treatment, participants who perceived assignment to bupropion versus placebo were not more likely to be abstinent (OR = 1.37; 95% CI 0.71–2.64, P = 0.35).The interaction between treatment and perceived treatment assignment was also nonsignificant. Consistent with two previous studies with bupropion, there was evidence of blinding failure for the treatment group. However, in our study, perceived treatment assignment did not significantly impact cotinine-verified cessation outcome at end-of-treatment (week 7). These findings suggest that the role of perceived treatment assignment on smoking cessation with bupropion may differ for light smokers compared to heavier smokers (&gt;10 cpd) sampled in the two earlier studies. Current findings might indicate that expectations of pharmacotherapy are less salient for light smokers.

Peripheral insulin and brain structure in early Alzheimer disease

OBJECTIVE

Accumulating evidence suggests insulin and insulin signaling may be involved in the pathophysiology of Alzheimer disease (AD). The relationship between insulin-mediated glucoregulation and brain structure has not been assessed in individuals with AD.

METHODS

Nondemented (Clinical Dementia Rating [CDR] 0, n = 31) and early stage AD (CDR 0.5 and 1, n = 31) participants aged 65 years and older had brain MRI to determine whole brain and hippocampal volume and 3-hour IV glucose tolerance tests to determine glucose and insulin area under the curve (AUC). Linear regression models were used to assess the relationship of insulin and glucose with brain volume, cognition, and dementia severity.

RESULTS

In early AD, insulin and glucose AUCs were related to whole brain (insulin beta = 0.66, p < 0.001; glucose beta = 0.45, p < 0.01) and hippocampal volume (insulin beta = 0.42, p < 0.05; glucose beta = 0.46, p < 0.05). These relationships were independent of age, sex, body mass index, body fat, cardiorespiratory fitness, physical activity, cholesterol, and triglycerides. Insulin AUC, but not glucose, was associated with cognitive performance in early AD (beta = 0.40, p = 0.04). Insulin AUC was associated with dementia severity (Pearson r = -0.40, p = 0.03). Glucose and insulin were not related to brain volume or cognitive performance in nondemented individuals.

CONCLUSIONS

Increased peripheral insulin is associated with reduced Alzheimer disease (AD)-related brain atrophy, cognitive dysfunction, and dementia severity, suggesting that insulin signaling may play a role in the pathophysiology of AD.

Effects of long-term aerobic exercise on EPOC

This study sought to determine the influence of 16 months of progressive aerobic exercise on excess postexercise oxygen consumption (EPOC) and the extent EPOC contributed to weight management. Twenty-five overweight/obese women and 16 overweight/obese men participated in a 16-month exercise program (moderate-intensity treadmill walking) that progressed across the first 26 weeks to 5 days.wk(-1), 45 min.session(-1), and 75% HRR. Three-hour EPOC was measured at baseline, 9 months, and 16 months by indirect calorimetry in response to an exercise session (treadmill walking), in which energy expenditure (EE) was estimated from the participant's previous 10 exercise sessions. For women, EPOC was 7.5 +/- 4.9, 9.6 +/- 7.6, and 6.5 +/- 6.5 L at baseline, 9 months, and 16 months, respectively (p > 0.05). For men, EPOC increased from baseline (11.8 +/- 6.8 L) to 9 months (13.5 +/- 8.6 L) (p < 0.05) with no further increase at 16 months (13.5 +/- 11.0 L). Change in EPOC was correlated with change in EE at 9 months (r = 0.65; p < 0.05) and 16 months (r = 0.58; p < 0.05) for men but not women. Progressive long-term exercise significantly influenced EPOC in overweight/obese men but not women. Change in volume of exercise likely explained the increase in energy expenditure during EPOC in men. EPOC contributed modestly to EE compared to the exercise itself.

Phase II breast cancer chemoprevention trial of the third generation selective estrogen receptor modulator arzoxifene

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Background: Arzoxifene (ARZ) is a third generation SERM with efficacy in metastatic breast cancer but lacking uterine agonist activity. Methods: We conducted a randomized, double-blind, placebo-controlled Phase II prevention trial in 199 high risk women assessing the effects of ARZ 20 mg/day on several risk biomarkers. Biomarkers, including cytomorphology of breast epithelial cells obtained by random periareolar FNA (RPFNA) were assessed at baseline and following 6 months of placebo or ARZ. Subjects were stratified by presence or absence of atypia, ER expression, BRCA1/2 mutation, as well as menopause status. Results: At entry, mean age was 47, 52% were premenopausal and 47% of postmenopausal women were taking HRT. Mean 10 year Gail was 6.8% and mean Masood cytology index score was 14.3. The ARZ and placebo groups were well matched. The protocol defined primary endpoint was a decrease in RPFNA cytology Masood index score by ≥3 points at 6 months and required 160 evaluable subjects for 81% power to detect a change from 30% to 52% of subjects showing improvement. For the 181 evaluable subjects, there was no significant difference in the proportion of women achieving ≥3 point improvement (19% placebo vs. 24% ARZ, p=0.46); or in change in mean index score (0.6 placebo vs. 0.9 ARZ, p=0.53). There was also no difference in grade 3 or 4 side effects or dropout prior to 6 months. However, comparing ARZ to placebo, there was favorable modulation of the two risk biomarkers, mammographic breast density (p=0.001) and IGF-1:IGFBP-3 ratio (p=0.001), and reduction in bone turnover biomarker osteocalcin (p= 0.002), but without an increase in endometrial thickness. Conclusions: Although improvement in cytomorphology after 6 months of ARZ was not shown, the acceptable side effect profile and favorable modulation of other biomarkers (breast density, IGF-1:IGFBP-3, osteocalcin) provides support for continued evaluation of ARZ as a breast cancer prevention agent.

No significant financial relationships to disclose.

Effect of the third generation selective estrogen receptor modulator arzoxifene on mammographic breast density

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Background: Arzoxifene (ARZ) is currently being studied for treatment of breast cancer patients in a Phase II trial because of tamoxifen-like efficacy but lack of uterine agonist effect. We conducted a Phase II chemoprevention trial in women at high risk for development of breast cancer on the basis of personal or family history. Methods: Potential subjects had multiple biomarkers assessed, including random periareolar fine needle aspiration (RPFNA) with breast epithelial cells processed for cytomorphology and immunocytochemistry. Women who exhibited cytologic hyperplasia ± atypia were eligible for enrollment. Subjects were stratified on the basis of atypia, estrogen receptor expression, menopause status, germline BrCa1/2 mutation status, and accrual site. Subjects were randomized (double-blind) between placebo and ARZ (LY353381.HCI, 20 mg daily) for 6 mo, with an option to continue on study for another 6 mo while receiving open-label ARZ. Assessments conducted at baseline, 6 mo, and 12 mo included mammographic breast density. Mammograms were digitized to image files which were cropped to remove labels and dates, and then identified by a study subject ID number and a random coding for baseline, 6 or 12 mo. This allowed the reader (GU) to view the three files for a subject, but to remain blinded as to the sequence of the films or the study agent. The files were assessed for mammographic density using the Madena computer-assisted system. Results: Of 199 subjects enrolled on the study, 52% were pre-menopausal; with 101 women randomized to placebo and 98 to ARZ. At baseline, mean values were comparable for placebo and ARZ groups for breast area (∼244 cm2), total dense area (∼100 cm2), and the percent of the breast at increased density (41.3% vs 46.2%). After 6 mo, there were minimal changes in total breast area (P=0.13); but statistically significant decreases (P<0.001) for the comparison of placebo vs ARZ (2-sided T-test) for change in both dense area (+3.8 vs −12.9 cm2) and percent breast density (+0.8% vs −4.6%). Conclusions: The 3rd generation SERM arzoxifene administered for 6 mo produces statistically significant decreases in mammographic breast density relative to placebo in women at high risk for development of breast cancer.

No significant financial relationships to disclose.

Breast-tissue sampling for risk assessment and prevention

Breast tissue and duct fluid provide a rich source of biomarkers to both aid in the assessment of short-term risk of developing breast cancer and predict and assess responses to prevention interventions. There are three methods currently being utilized to sample breast tissue in asymptomatic women for risk assessment: nipple-aspirate fluid (NAF), random periareolar fine-needle aspiration (RPFNA) and ductal lavage. Prospective single-institution trials have shown that the presence of atypical cells in NAF fluid or RPFNA specimens is associated with an increased risk of breast cancer. Furthermore, RPFNA-detected atypia has been observed to further stratify risk based on the commonly used Gail risk-assessment model. A prospective trial evaluating risk prediction on the basis of atypical cells in ductal-lavage fluid is ongoing. The ability of other established non-genetic biomarkers (mammographic breast density; serum levels of bioavailable estradiol, testosterone, insulin-like growth factor-1 and its insulin like growth factor binding protein-3) to stratify risk based on the Gail model is as yet incompletely defined. Modulation of breast intra-epithelial neoplasia (i.e. hyperplasia with or without atypia) with or without associated breast-tissue molecular markers, such as proliferation, is currently being used to evaluate response in Phase II chemoprevention trials. RPFNA has been the method most frequently used for Phase II studies of 6-12 months duration. However, ductal lavage, RPFNA and random and directed core needle biopsies are all being utilized in ongoing multi-institutional Phase II studies. The strengths and weaknesses of each method are reviewed.

A comparison of three methods of analyzing post-exercise oxygen consumption

Oxygen consumption after exercise is frequently plotted as a function of time and then the area under the curve (AUC) is calculated. Subsequently, this AUC is further manipulated and thus, differences between these manipulations may impact the interpretation of changes in oxygen consumption after exercise. The purpose of this study was to determine if the method of calculating AUC influences the interpretation of changes in post-exercise oxygen consumption in response to long-term aerobic exercise. Forty-three moderately obese, sedentary participants volunteered to participate in this study (26 women and 17 men). All participants performed verified supervised exercise during the study. Supervised treadmill exercise was initially conducted for 3 d/week at 60 % of heart rate reserve (HRR) for 30 min and progressed to 5 d/week at 75 % of HRR for 45 min across the first 4 months. Pre-exercise, exercise, and post-exercise oxygen consumption was measured at baseline and 9 months. AUC was calculated by three methods; total, incremental, and positive incremental. Descriptive statistics and dependent T-tests were calculated for each method of calculating the AUC. In addition, the intra-individual coefficient of variation was determined for each individual for each AUC method. A pearson product moment correlation was calculated for each method to determine the strength of the relationship between pre- and post-training values. The change in post-exercise oxygen AUC after nine months of training was 5.36+/-10.90 L, 2.17+/-7.61 L, and 1.74+/-9.10 L for the total, incremental, and positive incremental methods, respectively. There was significant change in post-exercise total AUC from baseline to 9-months (5.36 +/- 10.90 L), while there was no significant change in incremental or positive incremental AUC. There was a moderately high correlation (r=0.67, p <0.05) between baseline and 9-months for the total AUC method, while there was no significant correlation for incremental and positive incremental AUC methods. These results suggest that the method used to calculate AUC can lead to a different interpretation of the effects of training on post-exercise oxygen consumption. From this data, it appears that analyzing post exercise oxygen consumption with the total area under the curve method has a greater ability to detect a change from aerobic training, than either the positive or incremental area under the curve methods.

Active commuting to and from school and BMI in elementary school children-preliminary data

BACKGROUND

United States National Health Objectives include increasing the proportion of trips made by walking to and from school for children who live within 1.6 km to 50%. The purpose of this objective is to increase the level of physical activity among children. However, the impact of walking, bicycling or skating (active commuting) to and from school on the prevalence of overweight is unknown.

METHODS

Body mass index (BMI) was measured for 320 children (age 10.2+/-0.7 years) in September. Over 5 months, an active commuting index (SI) and daily physical activity were estimated via questionnaire. In April, BMI and body fat were measured.

RESULTS

A significant positive association was found between April BMI and SI adjusting for September BMI (partial r=0.03, P<0.05). Positive associations were found between SI and physical activity before school (r=0.17, P<0.05) and daily moderate intensity physical activity (r=0.13, P<0.05). There were no significant association between SI and BF (P>0.05).

CONCLUSIONS

This preliminary data suggests that active commuting does not appear to provide sufficient amounts of physical activity to attenuate BMI; however, it may contribute to the attainment of physical activity recommendations. Future research is needed to objectively measure the impact of active commuting on the prevalence of overweight.

Improved glycemic control with use of oral hypoglycemic therapy with or without insulin

OBJECTIVE

To determine whether combination oral hypoglycemic therapy in insulin-using patients with non-insulin-dependent diabetes mellitus (NIDDM) can improve glycemic control for a prolonged period.

METHODS

We expanded and extended an earlier study to include 130 patients with NIDDM for 10 to 30 years who had been using twice-daily mixed insulin for less than 10 years. Reduction and eventual elimination of the insulin therapy and substitution of metformin and a sulfonylurea were attempted. At follow-up visits, patients were weighed, random plasma glucose levels were determined, and glycosylated hemoglobin values were obtained.

RESULTS

Of 130 C-peptide-positive patients with NIDDM receiving twice-daily mixed insulin, 100 were successfully transferred to combination oral hypoglycemic therapy with glyburide originally and later glimepiride and metformin--a primary failure rate of 23.1%. Secondary failure occurred in 20 patients after a mean duration of 6.4 months. Two patients with successful conversion to oral combination therapy resumed insulin treatment because of cost. Of the patients with primary failures, 6 had gastrointestinal side effects, 10 were successfully managed on combination oral therapy plus evening mixed insulin, and 14 ultimately received twice-daily insulin and metformin. Of the secondary failures, 13 were controlled on combination oral therapy plus evening insulin and 7 on twice-daily insulin in conjunction with metformin. No difference was found in the original C-peptide levels among these three groups. Glycosylated hemoglobin levels were significantly less on combined oral hypoglycemic therapy (9.8% versus 8.3%; P = 0.0001), on combination oral therapy plus evening insulin (11.2% versus 9.7%; P = 0.001), and on return to twice-daily mixed insulin with metformin (11.0% versus 9.9%; P = 0.04). Those eight patients who resumed twice-daily insulin therapy alone, however, had a nonsignificant increase in glycosylated hemoglobin (9.3% versus 9.9%).

CONCLUSION

Improvement in glycosylated hemoglobin level in insulin-using patients with NIDDM can be obtained with combination oral therapy alone, combination oral therapy with once-daily evening insulin, or twice-daily mixed insulin with metformin in comparison with twice-daily insulin alone.

Smoking in urban African Americans: behaviors, gender differences, and motivation to quit

OBJECTIVE

This study describes smoking behaviors and gender differences, and correlates these factors with motivation to quit smoking among African-American smokers at a community-based health center.

DESIGN

A 62-item survey assessed depression, hassles, readiness to change, and demographics.

METHODS

Participants (N = 81) were interviewed in an adult clinic waiting room.

RESULTS

On average, participants smoked 13 cigarettes per day. Many reported attempts to reduce smoking-related health risks: 46% switched brands, 57% reduced their smoking, and 19% smoked only on some days. Fifty-nine percent indicated depressive symptoms. For women vs men, noteworthy differences were: reduction in number of cigarettes smoked (66.7% vs 40.0%; P = .023), switching brands (58.8% vs 23.3%; P = .003), number of attempts to quit in the past year (2.7 vs 1.2; P = .034), and high concern about weight gain (52.9% vs 26.7%; P = .047). Cigarettes smoked per day was negatively correlated with motivation to quit (P = .022). Variables positively correlated with motivation to quit included: harm reduction strategies (P = .002), intention to quit in 30 days (P<.0001), and intention to quit in 6 months (P<.0001).

CONCLUSIONS

Women showed more potential indications of readiness to quit, including more attempts to quit, reductions in number of cigarette smoked, and brand switching. Knowledge of cessation barriers, gender differences, and correlates to motivation may prove useful for investigators conducting research in this population.

Methylene blue chromoendoscopy for detection of short-segment Barrett's esophagus

BACKGROUND

The yield of intestinal metaplasia (IM) with randomly obtained biopsy specimens in patients with short lengths of columnar-appearing mucosa in the distal esophagus is low (30%-50%). Vital staining would be beneficial if it identified more patients with short-segment Barrett's esophagus (SSBE). Our aim was to compare the confirmation of IM in patients with suspected SSBE (columnar-appearing mucosa <3 cm in length) by using methylene blue (MB)-directed versus random biopsies.

METHODS

Consecutive patients undergoing EGD in whom columnar-appearing mucosa less than 3 cm in length was visualized underwent MB staining. Stained areas within suspected SSBE segments were targeted for biopsies. All biopsy specimens were stained with H & E with alcian blue at pH 2.5 and evaluated by a single pathologist. A historical control group (different from patients undergoing MB staining) consisted of patients with less than 3 cm of columnar-appearing mucosa in whom biopsy specimens were obtained randomly without MB staining.

RESULTS

The MB group included 75 patients (mean age 63.8 +/- 10.9 years) with a mean length of columnar-appearing mucosa of 1.2 cm (range 0.5-2.5 cm). The control group included 83 patients (mean age 60.5 +/- 12.9 years) with a mean length of columnar-appearing mucosa of 1.16 cm (range 0.5-2.5 cm). IM (i.e., confirmed SSBE) was detected in 61% of the MB group versus 42% of the control group (p = 0.0237). Patients in the MB group required significantly fewer biopsies (4.3 +/- 1.5 vs. 5.1 +/- 12.3, p = 0.0162). Confirmation of IM by length was as follows: less than 1 cm (irregular Z line), MB 17.4% versus control 25% (p = 0.73); 1 to less than 2 cm, MB 77% versus control 45% (p = 0.03); 2 to less than 3 cm, MB 90% versus control 58% (p = 0.02).

CONCLUSIONS

MB chromoendoscopy significantly increases the detection of IM and requires fewer biopsies in patients with suspected SSBE with greater than 1 cm of columnar-appearing mucosa. It does not appear to be beneficial in patients with irregular Z lines (<1 cm).

Differences among African American light, moderate, and heavy smokers

This study examined differences in demography, behavior, attitude, and physician intervention among African American light, moderate, and heavy smokers. Data were derived from an intervention study designed to assess whether a smoking status stamp would increase screening for smoking status and cessation counseling by physicians. Current analysis included 879 African American smokers categorized into three groups: light (<10 cigarettes/day), moderate (10-19 cigarettes/day), or heavy (> or =20 cigarettes/day) smokers based on number of cigarettes per day smoked. Light smokers constituted 40% of study sample, 33% were moderate smokers, and 27% were heavy smokers. Light smokers were more likely to be female (p<0.001) and have a shorter smoking history (p<0.001). Light smokers were not different in age (p=0.334), or the number of previous quit attempts (p=0.551). Although light smokers were more likely than moderate and heavy smokers to be preparing to quit (p<0.001), they were less likely to be asked their smoking status (p=0.031) or told to arrange follow-up for smoking cessation (p=0.034) by their physicians. Many African American smokers are light smokers. Light smokers are more likely to be female and have a shorter smoking history. Despite their readiness to quit, compared to heavier smokers, African American light smokers are asked about smoking less often by their physicians. Programs are needed to enhance physician intervention in this understudied population of smokers.

Cisplatin-induced response of c-jun N-terminal kinase 1 and extracellular signal--regulated protein kinases 1 and 2 in a series of cisplatin-resistant ovarian carcinoma cell lines

The cellular response to cisplatin involves activation of multiple signal transduction pathways, including the mitogen-activated protein (MAP) kinase pathways. In this study, we compared the cisplatin-induced activation of two MAP kinases, c-jun N-terminal kinase 1 (JNK1) and extracellular signal-regulated protein kinases 1 and 2 (ERK1/2), in the cisplatin-sensitive ovarian carcinoma cell line A2780 and its derivative cisplatin-resistant cell lines CP70 and C200. Dose-dependent and time-dependent activation of JNK1 and ERK1/2 occurred in each of the three cell lines in response to cisplatin treatment. The requirement of higher concentrations of cisplatin for induction of maximum activation of JNK1 and ERK1/2 was correlated with increased levels of cisplatin resistance. In addition, inhibition of cisplatin-induced ERK activation, using the MAP/ERK kinase 1 synthetic inhibitor PD98059, resulted in enhanced sensitivity to cisplatin in all three cell lines. These results suggest that cisplatin-induced ERK1/2 activity is not responsible for the acquired cisplatin resistance in CP70 and C200 cells but rather provides a general cytoprotective effect in both cisplatin-sensitive and cisplatin-resistant cell lines. In conclusion, different patterns of cisplatin-induced JNK1 and ERK1/2 activation are observed in cell lines with different levels of cisplatin sensitivity, and inhibition of cisplatin-induced ERK1/2 activation enhances sensitivity to cisplatin in both cisplatin-sensitive and cisplatin-resistant cell lines.

Helicobacter pylori eradication dramatically improves inflammation in the gastric cardia

OBJECTIVES

Inflammation of the gastric cardia, i.e., "carditis," has been associated with Helicobacter pylori (H. pylori) infection; however, some investigators believe carditis to be a histological marker for gastroesophageal reflux disease. The aim of this study was to investigate the role of H. pylori eradication on the grade of carditis scored according to the updated Sydney classification.

METHODS

Consecutive patients presenting for upper endoscopy underwent systematic gastric biopsies (eight antral, 12 corpus, and four cardia). Patients with H. pylori infection and carditis were identified and followed prospectively before and after H. pylori treatment. At pretreatment and, on average, 2 yr after eradication of H. pylori, the degree of inflammation in the gastric cardia and H. pylori status were blindly assessed by a single pathologist.

RESULTS

A total of 31 patients with H. pylori infection and carditis were identified. The mean age was 70 yr (range: 37-81 yr); all were male. Four were African-American and 27 were Caucasian. All patients were treated with standard anti-H. pylori therapy, including a proton pump inhibitor in combination with two antibiotics for 2 wk. Eradication of H. pylori was successful in 23 patients (group I), whereas eight patients had persistent infection (group II). Patients were followed after eradication therapy for a mean of 23.2 months (range: 6-48 months). After eradication therapy, there was a significant decrease (p < 0.0001) in the carditis scores (activity and inflammation scores) in group I, whereas the scores remained unchanged in group II patients. In both groups, there were no significant changes in the degree of intestinal metaplasia or atrophy. There were four patients with intestinal metaplasia, and one with atrophy.

CONCLUSIONS

There is a dramatic improvement in the degree of inflammation and activity scores in the gastric cardia of patients with successful H. pylori eradication compared to those with persistent infection. By fulfilling one of Koch's postulates (i.e., improvement in the disease after cure of the possible etiological organism), these data support H. pylori as being the etiological agent for carditis in this group of patients.

Homocysteine elevation in sickle cell disease

OBJECTIVE

Ischemic complications are common in patients with sickle cell disease. Hyperhomocysteinemia is a risk factor for arteriosclerosis and venous thrombosis, and given the propensity of patients with sickle cell disease to develop ischemic complications, we hypothesized that they might have elevated plasma homocysteine concentrations.

METHODS

Plasma concentrations of homocysteine, vitamin B12 and folate were measured in 49 adults with sickle cell disease and 16 normotensive Black controls. All subjects with sickle cell disease had been prescribed folic acid 1 mg by mouth daily.

RESULTS

The median plasma concentration of homocysteine of subjects with sickle cell disease was approximately 1.5-fold higher than that of controls (p=0.0008). This difference persisted, even when subjects with renal insufficiency were excluded. Plasma folate levels were 1.5-fold higher in subjects with sickle cell disease than in controls (p=0.0498). There was no significant difference in plasma vitamin B12 concentrations between the two groups. There was no difference in plasma homocysteine concentrations between transfused and non-transfused sickle cell subjects.

CONCLUSIONS

Patients with sickle cell disease have elevated plasma concentrations of homocysteine in spite of elevated plasma folate levels and vitamin B12 concentrations similar to those observed in controls. Based on these data, we hypothesize that the concentration of folate required to normalize plasma homocysteine levels in patients with sickle cell disease may be higher than that of normal controls and that patients with sickle cell disease have a higher nutritional requirement for folic acid than the general population.

Short-term breast cancer prediction by random periareolar fine-needle aspiration cytology and the Gail risk model

BACKGROUND

: Biomarkers are needed to refine short-term breast cancer risk estimates from epidemiologic models and to measure response to prevention interventions. The purpose of our study was to determine whether the cytologic appearance of epithelial cells obtained from breast random periareolar fine-needle aspirates or molecular marker expression in these cells was associated with later breast cancer development.

METHODS

: Four hundred eighty women who were eligible on the basis of a family history of breast cancer, prior precancerous biopsy, and/or prior invasive cancer were enrolled in a single-institution, prospective trial. Their risk of breast cancer according to the Gail model was calculated, and random periareolar fine-needle aspiration was performed at study entry. Cells were characterized morphologically and analyzed for DNA aneuploidy by image analysis and for the expression of epidermal growth factor receptor, estrogen receptor, p53 protein, and HER2/NEU protein by immunocytochemistry. All statistical tests are two-sided.

RESULTS

: At a median follow-up time of 45 months after initial aspiration, 20 women have developed breast cancer (invasive disease in 13 and ductal carcinoma in situ in seven). With the use of multiple logistic regression and Cox proportional hazards analysis, subsequent cancer was predicted by evidence of hyperplasia with atypia in the initial fine-needle aspirate and a 10-year Gail projected probability of developing breast cancer. Although expression of epidermal growth factor receptor, estrogen receptor, p53, and HER2/NEU was statistically significantly associated with hyperplasia with atypia, it did not predict the development of breast cancer in multivariable analysis.

CONCLUSION

: Cytomorphology from breast random periareolar fine-needle aspirates can be used with the Gail risk model to identify a cohort of women at very high short-term risk for developing breast cancer. We recommend that cytomorphology be studied for use as a potential surrogate end point in prevention trials.

Fractionated radiation therapy in combination with adenoviral delivery of the cytosine deaminase gene and 5-fluorocytosine enhances cytotoxic and antitumor effects in human colorectal and cholangiocarcinoma models

Radiosensitization of human gastrointestinal tumors by 5-fluorouracil (5-FU) has been studied in vitro and clinically in human cancer therapy trials. The bacterial enzyme cytosine deaminase (CD) converts the nontoxic prodrug 5-fluorocytosine (5-FC) into 5-FU. Human colon cancer cells stably expressing CD have been shown by other investigators to be sensitized to radiation following treatment with 5-FC. We previously used an adenoviral vector under control of the cytomegalovirus promoter (AdCMVCD) encoding the CD gene in combination with 5-FC and a single fraction of radiation exposure to enhance cytotoxicity to human cholangiocarcinoma cells in vitro and in vivo. The purpose of this study was to determine whether AdCMVCD infection and 5-FC with multiple fraction low-dose radiotherapy results in enhanced cytotoxicity. In the present study, we utilized AdCMVCD and 5-FC with single fraction radiotherapy to demonstrate enhanced cytotoxicity to WiDr human colon carcinoma cells in vitro. Additionally, we tested this gene therapy/prodrug treatment strategy employing a fractionated radiation dosing schema in animal models of WiDr colon carcinoma and SK-ChA-1 cholangiocarcinoma. A prolonged WiDr tumor regrowth delay was obtained with AdCMVCD infection in combination with systemic delivery of 5-FC and fractionated external beam radiation therapy compared with control animals treated without radiation, without 5-FC, or without AdCMVCD. The results of treatment with AdCMVCD + 5-FC + radiation therapy to cholangiocarcinoma xenografts were equivalent to those obtained with systemic 5-FU administration + radiation. Thus, the use of AdCMVCD can be effectively combined with clinically relevant 5-FC and radiation administration schemes to achieve enhanced tumor cell killing and increased control of established tumors of human gastrointestinal malignancies.

Growth of adolescents who were born at extremely low birth weight without major disability

OBJECTIVE

To compare growth between adolescents who were born at extremely low birth weight (ELBW, </=1000 g) and adolescents who were born at normal birth weight (NBW, >/=2500 g).

DESIGN/METHODS

Cross-sectional design. Fifty-three ELBW and 53 NBW adolescents without a major neurodevelopmental disability were matched by sex, race, age, and socioeconomic status. Anthropometrics (z scores), bone age, body composition (Lunar DPX-L densitometry), and sexual maturity were assessed. ELBW adolescents were classified as being born small for gestational age (SGA) or not (NSGA).

RESULTS

Subjects were 58.5% female, 43.4% black, and 56.6% white. The mean birth weight for ELBW subjects was 849 g and 3355 g for NBW subjects. The mean age was 14.85 years. On average, ELBW adolescents were 4.8 cm shorter and 9.1 kg lighter than NBW adolescents. ELBW adolescents had lower mean z scores for height (P <.0001), weight (P <.0001), and head circumference (P <.0001) than NBW adolescents. ELBW/SGA subjects had lower mean z scores for height (P <.0001) and weight (P =.001) than NBW subjects. Head circumference z scores were lower for the ELBW/SGA group than the ELBW/NSGA group or the NBW group (P =. 003). Sexual maturity and relative body composition were similar between groups. Bone age, measured in SD units, was more advanced in the ELBW group (0.86 vs. 0.42, P =.039).

CONCLUSIONS

ELBW adolescents who survive without a major neurodevelopmental disability attain lower growth measurements compared with NBW adolescents but have similar sexual maturation and relative body composition.

A robust summarize-regress procedure for tissue-specific pharmacokinetics

The destructive sampling necessary to obtain tissue-specific pharmacokinetics of radiolabeled ligands does not permit true time-dependent models to be estimated. To adjust for this, small groups of animals are sacrificed at varying time points and the percent injected dose per gram (PID) of radiolabeled ligands is summarized for each tissue of interest. Usually the average PID at each time point is modeled to obtain estimates of pharmacokinetic parameters for each tissue when utilizing summarize-regress procedures. In this paper, it is recommended that the median should be the summary measure at each time point to be modeled in these circumstances. The discrepancy that exists between modeling the average and median PID is demonstrated by an actual experiment. Finally, simulation studies are performed and the results are compared when using these two summary measures.

Prevalence and correlates of preventive care among adults with diabetes in Kansas

OBJECTIVE

To assess the prevalence and correlates of recommended preventive care among adults with diabetes in Kansas.

RESEARCH DESIGN AND METHODS

A cross-sectional telephone survey was conducted among a sample of adults (> or = 18 years of age) with self-reported diabetes. Recommended preventive care was defined based on four criteria: number of health-care provider (HCP) visits per year (> or = 4 for insulin users and > or = 2 for nonusers), number of foot examinations per year (> or = 4 for insulin users and > or = 2 for nonusers), an annual dilated eye examination, and a blood pressure measurement in the past 6 months.

RESULTS

The mean age of the 640 respondents was 61 years, 58% were women, and 86% were white. In the preceding year, 62% of respondents reported the appropriate number of visits to a HCP 27% the appropriate number of foot examinations, 65% an annual dilated eye examination, and 89% a blood pressure measurement in the preceding 6 months. Only 17% (95% CI 14-20) met all four criteria for recommended care. The adjusted odds of receiving recommended care were higher for males than for females (odds ratio [OR] 1.6; 95% CI 1.1-2.5), higher for people whose HCP scheduled follow-up appointments than for those who self-initiated follow-up (OR 2.7; 95% CI 1.6-4.8), and higher for former smokers than for current smokers (OR 3.1; 95% CI 1.6-6.9).

CONCLUSIONS

Preventive care for people with diabetes is not being delivered in compliance with current guidelines, especially for women and current smokers. Scheduling follow-up visits for patients, targeting certain high-risk populations, and developing protocols to improve foot care may be effective in improving care.

Reliability of treadmill measures and criteria to determine VO2max in prepubertal girls

PURPOSE

The main objective of this study was to determine the reliability of measuring treadmill exercise economy (VO2submax) and the maximal oxygen uptake (VO2max) in prepubertal girls tested twice, 6 wk apart. We also wanted to examine the percentage of young girls who were able to reach the criteria for achieving VO2max and to describe methods that would allow a high proportion of young children to achieve criteria for reaching a true VO2max.

METHODS

We studied 61 normal-weight, prepubertal girls with a mean (+/- SD) age 7.3+/-1.3 yr (range 4.8 to 10.3 yr). VO2submax was determined while walking for 4 min at 2.5 mph with 0% grade. VO2max was measured during a progressive, all-out, continuous treadmill test using standardized procedures and criteria. Heart rate (HR) was measured using a Polar monitor. Respiratory rate (RR), respiratory exchange ratio (RER), ventilation (V), and VO2 were measured using a Sensormedics metabolic monitor.

RESULTS

There were no significant differences between visits I and 2 in mean HR, RR, RER, V, VO2submax (421 vs 422 mL x min(-1), respectively), and VO2max (1036 vs 1049 mL x min(-1), respectively). Intra-individual coefficients of variation (CV) between visits 1 and 2 for submaximal tests were: HR = 5.1%, RR = 12.4%, RER = 7.2%, V = 12.5%, and VO2 = 12.4%. Intra-individual CVs for the maximum tests were: HRmax = 2.1%, RRmax = 10.8%, RERmax = 5.3%, Vmax = 11.7%, and VO2max = 7.5%. A high proportion of the girls reached criteria for VO2max [RER> 1.00, HR>85% of age predicted maximum, and plateauing of VO2max] in both visits: 99% reached one of three criteria, 92% reached two of three criteria, and 70% reached all three criteria. Twenty girls [mean age 7.2+/-1.2 yr] reached at least two criteria in both visits, whereas 32 girls [mean (+/- SD) age 8.6+/-1.0 yr] reached three criteria in both visits.

CONCLUSION

Exercise measurements using treadmill testing were reliable in healthy, normal-weight, prepubertal girls. Older girls when compared to the younger girls were able to reach criteria for VO2max more often. Thus, we recommend that one testing should give researchers an accurate measure of walking economy and aerobic capacity, and that two criteria are enough for determining VO2max.

Relative risk of dysplasia for patients with intestinal metaplasia in the distal oesophagus and in the gastric cardia

BACKGROUND

Biopsy specimens obtained from the gastro-oesophageal junction can reveal intestinal metaplasia in patients presenting for routine upper endoscopy. The site of biopsy may play a critical role in determining the dysplasia risk of a patient.

AIMS

To evaluate prospectively the dysplasia risk in patients with intestinal metaplasia of the distal oesophagus or within the gastric cardia.

METHODS

Patients with short segment Barrett's oesophagus (SSBO) and cardia intestinal metaplasia (CIM) were followed prospectively.

RESULTS

177 patients with SSBO were identified (mean age 62 years, range 38-82; 91% whites). Twenty prevalence cases of dysplasia in SSBO were detected: 17 low grade dysplasia (LGD), three high grade dysplasia (HGD). Seventy six patients with CIM were identified (mean age 67 years, range 37-81; 81% whites). A single prevalence case of LGD in CIM was detected. During follow up of 78 SSBO and 34 CIM patients, dysplasia developed in nine (seven LGD, two HGD) with SSBO and in one (LGD) with CIM. There were significant differences between the two groups with respect to age, ethnicity, dysplasia prevalence, and incidence. Time to dysplasia progression was significantly longer in CIM compared with SSBO patients. Of the five patients with SSBO and HGD, one developed adenocarcinoma of the oesophagus on follow up. No HGD or cancers have been detected over this time period in CIM patients.

CONCLUSIONS

The dysplasia risk is significantly greater in SSBO than in CIM patients, indicating two potentially different clinical processes. Future studies should separate SSBO from CIM in order to enhance the understanding of the pathophysiology and malignant potential of each entity.

Local recurrence following breast conservation therapy in African-American women with invasive breast cancer

BACKGROUND

African-American women have a lower survival rate than white women following a diagnosis of invasive breast cancer. Limited information is available regarding the impact of race on results of breast conservation therapy (BCT).

METHODS

Local recurrence rates were compared in 71 African-American patients (73 breasts) and 204 white patients (208 breasts) with stage I and II breast cancer treated with BCT.

RESULTS

Overall 5-year actuarial recurrence rates were 13% in African-Americans and 4% in whites (P = 0.075). These rates were 9% and 4%, respectively, if patients with local skin/soft tissue recurrences were excluded (P = 0.587). Exclusion of these skin/soft tissue failures eliminated any significant difference seen in recurrence between stage II African-American and white patients (P = 0.163). African-American women had less favorable recurrences, including tumor in more than one quadrant or local skin/ soft tissue involvement (P = 0.001).

CONCLUSIONS

Overall actuarial recurrence rates were slightly higher, but not significantly different, in African-American and white women following BCT. A much less favorable pattern of local recurrence was seen in the African-American patients (P = 0.001), which may represent the presence of more biologically aggressive tumors in these women.

Ciprofloxacin-warfarin coagulopathy: a case series

Ciprofloxacin, when given to patients previously anticoagulated with warfarin, can occasionally cause an exaggerated hypoprothombinemic response and bleeding diatheses. Two such cases encountered at our institution are presented and data is combined with 64 cases reported to the Food and Drug Administration's (FDA) Spontaneous Reporting System (SRS) database, which included all cases reported from 1987 through 1997. Of 66 total cases the median age was 72 (range 36-94). The mean time to detection of the coagulopathy following the ciprofloxacin challenge was 5.5 days (n = 50). Hospitalization was reported in 15 cases, bleeding in 25 cases, and death in one case. The median prothrombin time (PT) and International Normalized Ratio (INR) was 38.0 (n = 13) and 10.0 (n = 23), respectively. The mean number of medications taken was 6.5 (n = 45). The mean time to correction was significantly shorter between the treated (2.5 days) and the untreated (4.0 days) groups (P < 0. 008). The ciprofloxacin-warfarin coagulopathy occurred most commonly in patients in their seventh decade and in those who require polypharmacy. Active treatment of the coagulopathy results in more rapid resolution than observation alone. Clinicians should be aware of the potential bleeding complications that can occur with the ciprofloxacin-warfarin drug-drug interaction.

CT cystography: radiographic and clinical predictors of bladder rupture

OBJECTIVE

Our goal was to identify radiographic and clinical variables that correlate with bladder rupture that may then be used as selection criteria for CT cystography in trauma patients.

SUBJECTS AND METHODS

Hemodynamically stable trauma patients with hematuria were examined under standardized protocol with dynamic oral and i.v. contrast-enhanced CT of the abdomen and pelvis, followed immediately by CT cystography. CT cystography consisted of contiguous 5-mm axial scans of the pelvis after retrograde distention of bladder with 300-400 ml of 4% iodinated contrast material. Radiographic and clinical variables (pelvic fracture, pelvic fluid, intraabdominal visceral injury, degree of hematuria, hematocrit, units of blood transfused, base deficit, injury mechanism, seat belt use, sex, age) were assessed and statistically analyzed using the two-tailed Fisher's exact test and Wilcoxon's rank sum test. Positive and negative individual and multivariate predictors were analyzed.

RESULTS

Of the 157 patients entered in our study, 12 (eight males and four females) had bladder rupture. One or more pelvic fractures were present in nine (75%) of the 12 patients (p < 0.001). Pubic symphysis diastasis, sacroiliac diastasis, and sacral, iliac, and pubic rami fractures were statistically associated with bladder rupture. Isolated acetabular fractures did not correlate with rupture. Eight (67%) of the 12 patients with bladder rupture revealed on CT cystography had gross hematuria (p < 0.001). No ruptures were seen in patients with <25 RBC/HPF (red blood cells per high-power field). All patients with rupture had pelvic fluid revealed on standard contrast-enhanced CT (p < 0.001).

CONCLUSION

Gross hematuria, pelvic fluid, and specific pelvic fractures were highly correlated with bladder rupture; identification of these findings may help in selection of trauma patients for CT cystography.

Combined modality therapy of A431 human epidermoid cancer using anti-EGFr antibody C225 and radiation

BACKGROUND

Monoclonal antibodies (mAb) to epidermal growth factor receptor (EGFr) inhibit tumor cell proliferation and enhance cytotoxicity of chemotherapeutic agents. The purpose of this study was to investigate the interaction of the anti-EGFr antibody C225 combined with radiotherapy (RT) on EGFr expressing A431 human epidermoid cancer cells.

METHODS

Cell proliferation, apoptosis, EGFr expression and phosphorylation, and clonogenic survival were assayed in vitro. A431 tumor growth inhibition and immunohistochemistry analysis of EGFr expression and apoptosis were assessed in vivo.

RESULTS

C225 plus RT produced greater inhibition of A431 cell proliferation than C225 or RT alone which was corroborated by enhanced apoptosis. Similar clonogenic survival occurred following the addition of C225 to RT, although colonies were smaller in the presence of C225. C225 produced inhibition of EGF-induced phosphorylation of EGFr without concurrent down-regulation of surface receptor, which was not altered by RT. Combined treatment of mice bearing tumors demonstrated enhancement of complete regressions, reduction in time to tumor size doubling, and prolongation of survival. Significant apoptosis occurred in xenograft tumors treated with C225 with or without RT.

CONCLUSIONS

These data demonstrate an interaction between C225 and RT. C225-mediated apoptosis and inhibition of EGFr phosphorylation may be critical in the interaction. Studies to define the precise influence of combined modality treatment on the EGFr signal transduction cascade need to be pursued. The combination of growth factor receptor antibodies and RT has potential application in clinical oncology.

Improved synthesis of the bifunctional chelating agent 1,4,7,10-tetraaza-N-(1-carboxy-3-(4-nitrophenyl)propyl)-N',N'',N'''-tri s(acetic acid)cyclododecane (PA-DOTA)

A concise synthesis of the bifunctional chelating agent 1,4,7,10-tetraaza-N-(1-carboxy-3-(4-nitrophenyl)propyl)-N',N'',N'' '-tris(acetic acid)cyclododecane (PA-DOTA) is reported. Difficulties involving the production of partially alkylated products and their removal have been addressed and obviated. After the pure nitro form of PA-DOTA was obtained, conversion to the isothiocyanato form PA-DOTA (1, conjugation to HuCC49 and HuCC49deltaCH2 monoclonal antibodies was achieved. Subsequent radiolabeling with 177Lu was performed, demonstrating a useful bifunctional chelating agent suitable for clinical radioimmunotherapy applications.

Targeting strategies for cancer radiotherapy

Novel strategies to increase the therapeutic ratio in clinical radioimmunotherapy studies are needed. Limitations to radioimmunotherapy include bone marrow suppression due to the long circulating half-life of radiolabeled monoclonal antibodies (mAbs) and heterogeneous tumor penetration of the high-molecular-weight mAb. An approach to overcome these problems is the use of genetically engineered mAbs. The engineered mAb discussed in this paper contains a deletion in the constant region of the mAb that increases its tumor penetration and blood clearance compared with the intact mAb. Radiolabeling of this mAb should lead to a similar radiation-absorbed dose to tumor compared with the intact mAb, but reduce the radiation absorbed dose to bone marrow. In addition, low or variable expression of tumor-associated target antigens or receptors may lead to low or heterogeneous tumor uptake of radiolabeled mAbs. This report also discusses a novel approach toward systemic radiotherapy that combines gene transfer techniques (to increase tumor receptor expression) with radiolabeled peptides that target the induced receptor. The radiolabeled peptides achieve good tumor uptake, rapid tumor penetration, and rapid blood clearance. A humanized construct of the CC49 (HuCC49) high-affinity anti-TAG-72 mAb, as well as a construct with the CH2 region deleted (HuCC49deltaCH2), were labeled with 131I and 177Lu. Biodistribution of the radiolabeled constructs was evaluated 24 h after regional i.p. injection in athymic nude mice bearing i.p. LS174T human colon cancer xenografts. The 131I-HuCC49deltaCH2 showed a median tumor uptake of 5.5% ID/g which was similar to that of 131I-HuCC49 at 5.2% ID/g. However, the median blood concentration of 131I-HuCC49deltaCH2 was 0.2% ID/g which was significantly lower than 0.8% ID/g for 1311-HuCC49. The uptake of the constructs in other normal tissues were similar. The 177Lu-HuCC49deltaCH2 showed a median tumor uptake of 9.4% ID/g, which was slightly higher than that of 177Lu-HuCC49 at 7.9% ID/g. The median blood concentration of 177Lu-HuCC49deltaCH2 was 0.2% ID/g, which was significantly lower than 0.4% ID/g for 177Lu-HuCC49. The uptake of the antibody constructs in other normal tissues were similar except for the kidney. The tumor:blood ratios of 177Lu-HuCC49 and 177Lu-HuCC49deltaCH2 were 19.4 and 60.2, respectively, at 24 h after injection. The purpose of the second aspect of the study was to determine the biodistribution of 64Cu-1,4,8,11-tetraazacyclotetradecane-1,4,8,11-tetraacetic acid (TETA)-octreotide in a human ovarian cancer model induced to express human somatostatin receptor subtype 2 (SSTr2) using gene transfer techniques as a prelude to future therapy studies. Mice bearing i.p. SKOV3.ip1 tumors transduced with an adenoviral vector encoding the cDNA for SSTr2 (AdSSTr2) and injected i.p. with 64Cu-TETA-octreotide showed a median uptake of 24.3% ID/g in tumor at 4 h postinjection compared with 4.9% ID/g at 18 h after injection. Also, tumor uptake of 64Cu-TETA-octreotide at 4 h was not significantly different when administered either 2 or 4 days after injection of AdSSTr2 (P = 0.076). 64Cu-TETA-octreotide should be useful for targeted radiotherapy against tumors that are genetically induced to express high levels of SSTr. These two novel targeting strategies show promise for improved cancer radioimmunotherapy.

Comparison of multiple bolus and continuous injections of 131I-labeled CC49 for therapy in a colon cancer xenograft model

One of the problems in achieving cures with radioimmunotherapy is that hematological toxicity limits the quantity of radiolabeled monoclonal antibody (MAb) that can be administered. The MAb CC49 binds with high affinity to the TAG-72 antigen expressed in many human adenocarcinomas. We investigated tumor growth inhibition, survival, and tumor and bone marrow dosimetry after multiple bolus injections or continuous infusion of 131I-labeled CC49 MAb in a human colon cancer xenograft model to determine which method of administration results in the highest therapeutic ratio. Groups of athymic nude mice bearing established s.c. LS174T human colon cancer xenografts received three i.p. bolus injections (3X) of 131I-labeled CC49 (3X, days 0, 3, and 7) or were implanted i.p. with mini-osmotic pumps delivering 131I-labeled CC49 over 7 days. The total radionuclide doses administered were broken down into low-dose (< or = 450 microCi), medium-dose (450-800 microCi), and high-dose (> 800 microCi) groups. At the medium-dose level, the bolus-therapy animals did not have a significantly longer survival time but did have a significantly longer time-to-tumor doubling than the pump-therapy animals. The median survival for medium-dose bolus and pump therapy was 157 and 105 days, respectively, and the median time-to-tumor doubling was at least 114 and 77 days, respectively. At the low-dose level, the bolus-therapy animals had a significantly longer survival time but not a significantly longer time-to-tumor doubling than the pump-therapy animals. The median survival for low-dose bolus and pump therapy was 95.5 and 59 days, respectively, and the median time-to-tumor doubling was 73 and 38 days, respectively. The high-bolus dose was toxic. A comparison of the overall survival rate of pump therapy versus bolus therapy, excluding high-dose, resulted in the bolus-therapy animals having a longer survival time and a longer time-to-tumor doubling than the pump-therapy animals. Serial section autoradiography was used to reconstruct tumor activity density distributions over time. Average dose values calculated from total uptake data for 900 microCi administered activity yielded 158 Gy (3X) and 141 Gy (pump). Average three-dimensional doses using the radial histograms to calculate the absorbed fractions were 139 Gy and 123 Gy, respectively. This calculation includes energy loss external to the tumor. With cell proliferation parameters set to single fraction 60Co recurrence results, the effective dose (D(eff)) for local control was 11 Gy and 9 Gy, respectively. Three bolus injections resulted in a more uniform dose rate over a longer period, resulting in a calculated 19% improvement in D(eff) compared with pump administration. Dose to bone marrow was calculated assuming an activity concentration in bone marrow of 0.24 times the concentration in blood and an absorbed fraction of 0.63. For the 900-microCi 131I-labeled CC49 injected activity, pump administration resulted in an 80% higher calculated D(eff) to bone marrow compared with 3X bolus injection. These results demonstrate that 3X bolus injections were clearly superior to pump administration in terms of survival, tumor growth inhibition, tumor absorbed dose, and bone marrow dose.

Biodistribution study of 188Re-labeled trisuccin-HuCC49 and trisuccin-HuCC49deltaCh2 conjugates in athymic nude mice bearing intraperitoneal colon cancer xenografts

The trihydroxamate bifunctional chelating agent (BCA), trisuccin, has been shown to be a potential ligand for radiolabeling of monoclonal antibodies (MAbs) with rhenium radioisotopes, through an indirect postconjugation approach. The use of this trihydroxamate BCA made it possible to prepare stable BCA-MAb conjugates in pure form that could be radiolabeled with carrier-free 188Re. The anti-TAG-72 murine MAb, CC49, and its humanized derivatives are promising agents in the treatment of a number of malignancies with the CH2 domain-deleted MAb (HuCC49deltaCH2), which is of particular interest due to its rapid blood clearance. The biodistribution of 188Re-labeled conjugates of trisuccin with both humanized CC49 (HuCC49) and HuCC49deltaCH2 in athymic nude mice implanted i.p. with LS174T human colon carcinoma was studied. Trisuccin-MAb conjugates were synthesized at different BCA:MAb ratios by the 6-oxoheptanoic acid method using trisuccin hydrazide. The conjugates were analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectroscopy for the number of incorporated trisuccin molecules. The conjugates were radiolabeled with carrier-free, generator-produced 188Re and purified by gel filtration on Sephadex G-25. Labeling yields and homogeneity of the labeled conjugates were analyzed by high-pressure liquid chromatography and instant TLC. Athymic nude mice were injected i.p. with LS174T human colon carcinoma cells, 7 days prior to injection of the labeled antibodies. 188Re-labeled MAbs were injected i.p., and the mice were sacrificed 24 h postinjection. Matrix-assisted laser desorption/ionization time-of-flight analyses showed stable incorporation of trisuccin into each MAb, with the measured ligand:MAb values positively correlating with the theoretical ratios. Labeling of the conjugates with 188Re proceeded with high yields, producing homogeneous 188Re-MAbs with good stabilities as shown by instant TLC and biodistribution analyses. Biodistribution of the radiolabeled MAbs at 24 h after injection showed median tumor uptake values of 23.5%ID/g and 17.6%ID/g for the 188Re-HuCC49deltaCH2 and 188Re-HuCC49, respectively. The blood clearance of the domain-deleted MAb was faster than that of the intact antibody. The blood values at 24 h after injection were 0.7%ID/g for 188Re-HuCC49deltaCH2 and 3.2%ID/g for 188Re-HuCC49. The results indicate that trisuccin is a promising agent for postconjugation labeling of antibodies with 188Re. Additionally, these results illustrate the potential of 188Re-HuCC49deltaCH2 in radioimmunodiagnosis and radioimmunotherapy of cancer.

Limited local and systemic antibody responses to Neisseria gonorrhoeae during uncomplicated genital infections

Repeated infections with Neisseria gonorrhoeae are common among patients attending sexually transmitted disease clinics. We examined whether previous infections or site of infection altered the local and systemic antigonococcal antibody levels in males and females. Antibodies against N. gonorrhoeae MS11 and the patients' homologous infecting isolates were measured by enzyme-linked immunosorbent assay. In general, the local and systemic immune responses to gonococci were extremely modest. There was a slight increase in serum immunoglobulin G (IgG) against the MS11 strain and the homologous isolates in infected males. Levels of serum IgA1 antibodies against MS11 were slightly higher in infected than in uninfected females. A history of previous infections with N. gonorrhoeae did not alter the antibody levels in patients with a current infection, suggesting that immunological memory is not induced by uncomplicated gonococcal infections. Antibody responses to infected subjects' homologous isolates were observed in cervical mucus; IgA1 levels increased while IgG levels decreased. The decline in mucosal IgG against the homologous isolates was less common in subjects having both rectal and cervical infections; otherwise, no effect of rectal involvement was observed. The absence of substantially higher antibody levels to gonococci where there is infection at a site known to contain organized lymphoid tissue suggests that the low levels of responses to uncomplicated infections may not be due simply to an absence of inductive sites in the genital tract. We propose that in addition to its potential ability to avoid the effects of an immune response, N. gonorrhoeae does not elicit strong humoral immune responses during uncomplicated genital infections.

Fatty acid synthase expression is increased in neoplastic lesions of the oral tongue

BACKGROUND

Fatty acid synthase (FASE) is required for fatty acid synthesis. Elevated levels of FASE have been observed in a variety of malignancies.

METHODS

We examined the expression of FASE in 56 primary squamous cell carcinomas (SCC) of the tongue using immunohistochemistry (IHC) with a monoclonal antibody to FASE.

RESULTS

Immunoreactivity was low in histologically normal epithelium (0.42 +/- .07, n = 43), moderate in mildly dysplastic epithelium (1.41 +/- 11, n = 40), and strong in SCC of the tongue (1.64 +/- 10, n = 50). Both mild dysplasia and SCC stained more strongly than histologically normal epithelium (p<0.00001). Well-differentiated tumors showed increased immunoreactivity when compared to less well-differentiated tumors (p=0.044). Decreased overall survival was observed among patients with tumors with low immunoreactivity (p = 0.04).

CONCLUSIONS

Increased expression of FASE in dysplasia and squamous carcinomas of the oral tongue may be an indicator of both differentiation and early neoplastic change. FASE expression may be useful diagnostically, prognostically, and as a potential target for therapy.

Evaluating overall significance levels in multifactor ANOVA

Multifactor ANOVA procedures are commonly used by practitioners. A hierarchical process for testing the interaction effect(s) first, followed by tests for the main effects, is usually employed. Generally, no consideration is given to the overall type I error rate for these dependent (or conditional) tests. In this article, we formulate a method to evaluate the true overall significance levels for two-factor fixed-effect ANOVA models. Methods for evaluating conditional p-values are discussed. We present the overall significance levels for several specific two-factor designs. We discuss upper bounds on the overall significance level and extensions of the computational methods to higher-order designs as well as applications to random-effect models and mixed models.

In vivo localization of [(111)In]-DTPA-D-Phe1-octreotide to human ovarian tumor xenografts induced to express the somatostatin receptor subtype 2 using an adenoviral vector

Adenoviral vectors, encoding genes for cell surface antigens or receptors, have been used to induce their high level expression on tumor cells in vitro and in vivo. These induced antigens and receptors can then be targeted with radiolabeled antibodies or peptides for potential radiotherapeutic applications. The purpose of this study was to determine a dosing schema of an adenoviral vector encoding the human somatostatin receptor subtype 2 (AdCMVhSSTr2) for achieving the highest tumor localization of [(111)In]-DTPA-D-Phe1-octreotide, which binds to this receptor, in a human ovarian cancer model as a prelude to future therapy studies. AdCMVhSSTr2 was produced and used to induce hSSTr2 on A427 human nonsmall cell lung cancer cells and on SKOV3.ipl human ovarian cancer cells in vitro, as demonstrated by competitive binding assays using [125I]-Tyr1-somatostatin and [(111)In]-DTPA-D-Phe1-octreotide. Mice bearing i.p. SKOV3.ip1 tumors administered 1 x 10(9) plaque-forming units of AdCMVhSSTr2 i.p. 5 days after tumor cell inoculation, followed by an i.p. injection of [(111)In]-DTPA-D-Phe1-octreotide 2 days later, showed a range of 15.3-60.4% median injected dose/gram (ID/g) in tumor at 4 h after injection compared with 3.5% ID/g when [125I]-Tyr1-somatostatin was administered and 0.3% ID/g when the negative control peptide [125I]-mIP-bombesin was administered. Mice administered a control adenoviral vector encoding the gastrin-releasing peptide receptor did not have tumor localization of [(111)In]-DTPA-D-Phe1-octreotide (<1.6% ID/g), demonstrating specificity of [(111)In]-DTPA-D-Phe1-octreotide for the AdCMVhSSTr2 induced tumor cells. In another set of experiments, the tumor localization of [(111)In]-DTPA-D-Phe1-octreotide was not different 1, 2, or 4 days after AdCMVhSSTr2 injection (31.8, 37.7, and 40.7% ID/g, respectively; P = 0.88), indicating that multiple injections of radiolabeled peptide can be administered with equivalent uptake over a 4-day period. [(111)In]-DTPA-D-Phe1-octreotide tumor localization in animals administered AdCMVhSSTr2 on consecutive days or 2 days apart was 22.4% ID/g and 53.2% ID/g, respectively (P = 0.009) when [(111)In]-DTPA-D-Phe1-octreotide was given 1 day after the second AdCMVhSSTr2 injection. There was no difference in [(111)In]-DTPA-D-Phe1-octreotide localization after a single AdCMVhSSTr2 injection (40.7% ID/g) or two injections of AdCMVhSSTr2 given 1 (45.9% ID/g) or 2 (53.2% ID/g) days apart, where [(111)In]-DTPA-D-Phe1-octreotide was given in each case 4 days after the first AdCMVhSSTr2 injection (P = 0.65). Therefore, two AdCMVhSSTr2 injections did not increase [(111)In]-DTPA-D-Phe1-octreotide tumor localization compared with one injection, which eliminates concerns about an immune response to a second dose of AdCMVhSSTr2. This will be the basis for a therapeutic protocol with multiple administrations of an octreotide analogue labeled with a therapeutic radioisotope.

B lymphocyte migration to the bone marrow of humans is not random

This research is a result of analysing a total of 20 independently isolated immunoglobulin gene sequences from a defined population of mature B cells found in the bone marrow of five healthy adults. Each individual exhibited at least two identical gene sequences in our sample. Each variable immunoglobulin sequence is the product of the recombination of three gene segments, V, D and J genes. All sequences sampled contained a specific V gene, V5-51. Comparing the particular J and D genes expressed together with V5-51 as well as the junctional modifications between these genes established the relatedness of the sequences. The likelihood of finding at least two out of k identical gene sequences, if they occur randomly, is found and compared to the experimentally determined sequences. We conclude that it is unlikely that the B cells containing the related sequences found in the bone marrow is by chance. This suggests that this particular population of B cells migrate to the bone marrow in a co-ordinated fashion.

Differential susceptibility of primary and established human glioma cells to adenovirus infection: targeting via the epidermal growth factor receptor achieves fiber receptor-independent gene transfer

Adenovirus (Ad) vectors are promising for gene therapy of glioma due to their ability to achieve efficient gene transfer upon intratumoral administration. Yet in this context, Ad mediates widespread gene transfer to both tumor and surrounding parenchyma. Ad entry is dependent upon the expression of fiber receptors, such as coxsackie/adenovirus receptor, and alpha(v) integrins on the target cells for binding and internalization, respectively. We hypothesized that the susceptibility of human gliomas to Ad would likely be heterogeneous due to variable expression of these receptors. It was found that established human glioma cell lines exhibited differential susceptibility to Ad-mediated gene transfer, which correlated directly with the level of radiolabeled Ad binding and with the expression of coxsackie/adenovirus receptor but not with the expression of alpha(v) integrins. To circumvent the lack of fiber receptors and to target Ad gene transfer specifically to tumor cells, we used a bispecific antibody conjugate to ablate Ad binding to fiber receptors and retarget binding to the epidermal growth factor receptor (EGFR), a tumor-associated marker negligibly expressed in normal, mitotically quiescent neural tissues. The results demonstrate that EGFR-targeted Ad gene transfer was EGFR specific and independent of fiber-fiber receptor interactions. Furthermore, EGFR targeting significantly enhanced Ad gene delivery to 7 of 12 established glioma cell lines and to 6 of 8 cultured primary gliomas. Interestingly, EGFR-targeted Ad gene transfer did not correlate with EGFR expression across cell lines, suggesting the importance of other factors. This study establishes that fiber receptor expression limits the utility of Ad vectors for gene transfer to glioma cells and suggests that targeting Ad via EGFR may prove valuable for tumor-specific gene transfer to high-grade gliomas. These findings have key relevance in the context of Ad vector-based approaches for glioma gene therapy.

Evaluation of immunoglobulin A1 (IgA1) protease and IgA1 protease-inhibitory activity in human female genital infection with Neisseria gonorrhoeae

Immunoglobulin A1 (IgA1) protease, an enzyme that selectively cleaves human IgA1, may be a virulence factor for pathogenic organisms such as Neisseria gonorrhoeae. Host protection from the effects of IgA1 protease includes antibody-mediated inhibition of IgA1 protease activity, and it is believed that the relative balance between IgA1 protease and inhibitory antibodies contributes to the pathogenesis of disease caused by IgA1 protease-producing organisms. We have examined the levels of these two opposing factors in genital tract secretions and sera from women with uncomplicated infection with N. gonorrhoeae. When IgA1 in cervical mucus was examined by Western blotting, no evidence of cleavage fragments characteristic of IgA1 protease activity was seen in gonococcus-infected or control patients. Cleavage fragments typical of IgA1 protease were detected, however, after the addition of exogenous IgA1 protease to cervical mucus. Degraded IgA1 was detected in some vaginal wash samples, but the fragment pattern was not typical of IgA1 protease activity. All N. gonorrhoeae isolates from the infected patients produced IgA1 protease in vitro. All but two serum samples and 16 of 65 cervical mucus samples displayed inhibitory activity against gonococcal IgA1 protease, but there was no significant difference in the level of inhibitory activity between gonococcus-infected and noninfected patients in either cervical mucus or serum. There was no difference in the levels of IgA1 protease-inhibitory activity in serum or cervical mucus collected from patients at recruitment and 2 weeks later. These results suggest that cleavage of IgA1 by gonococcal IgA1 protease within the lumen of the female lower genital tract is unlikely to be a significant factor in the pathogenesis of infections by N. gonorrhoeae.

Weight Loss in Patients With Diabetes Treated with A Metformin-Sulfonylurea Combination in Comparison with Twice-Daily Mixed Insulin

OBJECTIVE

To investigate whether patients previously treated with insulin or sulfonylureas alone can be transferred to a combination of sulfonylureas and metformin therapy and realize a prolonged weight loss.

METHODS

We conducted a retrospective review of medical records to identify three groups of patients with type 2 diabetes: group 1, those requiring insulin who had remained on a daily regimen of two injections of mixed insulin; group 2, patients whose regimen had been changed from sulfonylureas alone to a combination of a sulfonylurea and metformin; and group 3, patients whose regimen had been converted from twice-daily mixed insulin alone to a sulfonylurea-metformin combination. Results relative to loss of weight in these three groups were analyzed.

RESULTS

For a 12-month period, no significant weight loss was noted in group 1, and group 2 showed a small nonsignificant weight loss in 6 months. Only group 3 had a significant weight loss at 3, 6, 9, and 12 months, maximizing at a mean weight loss of 22 lb (10 kg) at 12 months. In addition, in those patients in whom data were available, a significant weight loss was found at 18 and 21 months. At 21 months, however, weight began to increase. Percentage weight loss followed a pattern similar to that seen with total weight loss. The proportion of patients losing weight did not differ significantly in groups 1 and 2; however, in group 3, after 3 and 12 months a significant proportion of patients (79% and 86%, respectively) had lost weight. Race, gender, or baseline body weight had no effect on weight loss.

CONCLUSION

From this retrospective study of patients with type 2 diabetes, we conclude that conversion from insulin to combination oral therapy with sulfonylureas and metformin results in a significant weight loss for up to 21 months.

Radiosensitization mediated by a transfected anti-erbB-2 single-chain antibody in vitro and in vivo

PURPOSE

The erbB-2 receptor is overexpressed in several human cancers, including ovarian, prostate, and breast. We have developed plasmid and adenoviral vectors expressing an anti-erbB-2 single chain antibody (sFv), directed to the endoplasmic reticulum (ER) of target cells, that is cytotoxic to tumor cells overexpressing erbB-2 through induction of apoptosis. The anti-erbB-2 sFv also sensitizes erbB-2 overexpressing cells to the cytotoxic effects of cisplatin. On this basis, we hypothesized that human ovarian cancer cells expressing anti-erbB-2 sFv with downregulated erbB-2 product, p185erbB-2, also would be sensitized to ionizing radiation. Therefore, we designed experiments to test the ability of the anti-erbB-2 sFv to radiosensitize human ovarian cancer cells in vitro and in vivo.

METHODS AND MATERIALS

To test our hypothesis, we established subcutaneous (s.c.) tumors in the flanks of nude mice with SKOV3.ip1 human ovarian cancer cells and SKOV3 cells stably expressing the ER directed anti-erbB-2 sFv (SKOV3/pGT21). The tumors were treated with 10 Gy 60Co, or received no radiation. We then determined the regression rate, delay in regrowth, and time to tumor doubling of the tumors treated with radiation in the transfected group and controls. In addition, SKOV3.ip1 and SKOV3/pGT21 tumors were dissected from the irradiated animals and assayed for differences in p185erbB-2 expression at 12 weeks after irradiation by immunohistochemistry. Further, in vitro clonogenic survival assays were performed on the parental SKOV3.ip1 and SKOV3/pGT21 cell lines.

RESULTS

A statistical analysis of the combined data was done for two in vivo experiments. The analysis of the combined data showed that animals with irradiated tumor SKOV3/pGT21 had a significantly higher regression rate (p = 0.0055), longer delay in regrowth (p = 0.0001) and time to tumor doubling (p = 0.0004), than those animals with tumor SKOV3.ip1 that received radiation. We observed a similar significant effect for the same parameters in the unirradiated tumor SKOV3/pGT21 compared to unirradiated tumor SKOV3.ip1. Immunohistochemical analysis of the SKOV3/pGT21 tumor cells demonstrated focal accumulation of p185erbB-2 in scattered clumps of cells and less p185erbB-2 membrane expression than cells of SKOV3.ip1 tumors. However, SKOV3.ip1 and SKOV3/pGT21 cells had similar in vitro sensitivity to radiation.

CONCLUSIONS

These data support the hypothesis that tumors with reduced p185erbB-2 expression mediated by the anti-erbB-2 sFv are rendered more susceptible in vivo to the cytotoxic effects of ionizing radiation than tumors that maintain their normal expression of p185erbB-2. However, a similar effect was not observed with the same tumor cells in vitro. Thus, as has been described by others (1, 2), in vitro and in vivo results do not always correlate. Therefore, appropriate assays to assess clinical relevance need to be determined for each particular system studied.

Variability of abdominal adipose tissue measurements using computed tomography in prepubertal girls

OBJECTIVE

To determine the variability of measuring regional adipose tissue area using abdominal computed tomography (CT) in normal-weight, prepubertal girls.

DESIGN

Measurements of abdominal CT were performed twice, 6 weeks apart.

SUBJECTS

Sixty-one normal-weight, prepubertal girls (age: 4.8-10.3 y, mean (s.d.) BMI: 16.7 +/- 1.5 kg/m2).

MEASUREMENTS

Abdominal adipose tissue by CT at baseline and 6 weeks later.

RESULTS

There were no significant differences between visits 1 and 2 with regard to the children's average abdominal CT derived intraabdominal adipose tissue (21.64 cm2 vs 23.74 cm2) and subcutaneous adipose tissue (62.49 cm2 vs 65.28 cm2). The Pearson coefficient of correlation (r), P-value, total coefficient of variation (CV) and standard error of the difference (SEdelta) for intra-individual measurements between visits 1 and 2 by abdominal CT were: total abdominal adipose tissue, r = 0.94, P < 0.0001, CV = 12.34%, SEdelta 2.25 cm2; subcutaneous abdominal adipose tissue, r = 0.96, P < 0.0001, CV = 10.67%, SEdelta = 1.57 cm2; and intraabdominal adipose tissue, r = 0.67, P < 0.0001, CV = 21.5%, SEdelta = 1.11 cm2. The mean ratios of intraabdominal to subcutaneous adipose tissue on visits 1 and 2 were 0.42 +/- 0.2 and 0.44 +/- 0.24, respectively.

CONCLUSION

Regional adipose tissue area measurements using abdominal CT were reliable in healthy, normal-weight, prepubertal girls.

Body composition changes in Caucasian and African American children and adolescents with obesity using dual-energy X-ray absorptiometry measurements after a 10-week weight loss program

OBJECTIVE

Changes in body composition during a weight loss program have not been described in children. We wanted to test the hypothesis that weight loss can be achieved while maintaining total body fat-free mass.

RESEARCH METHODS AND PROCEDURES

We determined body composition changes by using dual-energy X-ray absorptiometry measured at baseline and after the first 10 weeks of a multidisciplinary weight loss program. The program consisted of 10 weekly group sessions where the children were provided instruction in lifestyle modification, including diet and exercise. Program leaders included a pediatrician, psychologist, registered dietitian, and exercise instructor.

RESULTS

We studied 59 obese children, mean (+/-SD) age 12.8+/-2.6 years, 29% boys and 71% girls, 49% Caucasian, and 51% African American. At enrollment, the children's mean height and body mass index were 157 cm and 38.9 kg/m2, respectively. The children's dual-energy X-ray absorptiometry-derived mean at baseline and at 10 weeks and corresponding p values were: weight (94.6 kg vs. 92.3 kg, p<0.0001), total body fat mass (46.9 kg vs. 44.3 kg, p<0.0001), percentage total body fat (49.2% vs. 47.5%, p<0.0001), total trunk mass (43.0 kg vs. 41.5 kg, p<0.0001), total trunk fat (21.2 kg vs. 20.0 kg, p<0.0001), total body fat-free mass (47.6 kg vs. 47.9 kg, p=0.33), total body bone mass (2.7 kg vs. 2.7 kg, p=0.99), and total body bone mineral density (1.14 g/cm2 vs. 1.15 g/cm2, p=0.0119). The children's race, gender, or Tanner stage did not affect these changes.

DISCUSSION

Decreases in total body fat mass was achieved, and total body fat-free mass was maintained among boy and girl Caucasian and African American children participating in this lifestyle modification weight loss program.

Immunologic response to the dual murine anti-Id vaccine Melimmune-1 and Melimmune-2 in patients with high-risk melanoma without evidence of systemic disease

Melimmune is a dual preparation of two murine anti-idiotypic antibodies (anti-Ids), Melimmune-1 and Melimmune-2, which mimic separate epitopes of the melanoma-associated high molecular weight proteoglycan antigen. In an animal model, vaccination with either anti-Id leads to tumor rejection, and Phase I clinical trials have demonstrated the tolerance of each reagent in humans. We conducted a Phase IB trial of different doses of a one-to-one composition to Melimmune-1 and Melimmune-2 administered with SAF-m adjuvant in patients with resected melanoma without evidence of metastatic disease. A total of 21 patients were enrolled in this multicenter trial. Detailed immune response analysis was conducted on 13 patients enrolled at a single institution. Following vaccination, 12 of the 13 patients demonstrated antibodies to both Melimmune-1 and Melimmune-2, including significant anti-V-region reactivity. Maximum anti-V-region reactivity was generally detected following the last vaccination. Anti-V-region reactivity directed at Melimmune-1 and Melimmune-2 in excess of 1 microgram/ml was detected in 4 and 10 of 12 patients, respectively. Sera from patients obtained at time of peak anti-V-region reactivity did not demonstrate the ability to inhibit Ab1 binding to tumor cells or direct anti-tumor cell reactivity. However, in vitro cellular proliferation was observed in response to Melimmune-1 and/or Melimmune-2 F(Ab')2 in all patients with a mean stimulation index of 12.0 and 27.8, respectively. Overall, the antibody and cellular immune response to Melimmune-2 was more potent than to Melimmune-1, and all antibody doses elicited an immune response. The optimal biologic dose of Melimmune could not be determined in this small patient population.