Review of outcome measurement instruments in Alzheimer's disease drug trials: psychometric properties of global scales

The use of global outcome measures with strong psychometric properties in Alzheimer's disease (AD) drug trials is encouraged. This article focuses on Clinician Global Impression of Change scales, the Clinical Dementia Rating, and the Global Deterioration Scale to provide (1) a review of psychometric properties, (2) a critique of how these properties are assessed in the literature, and (3) a basis for evaluating, from the standpoint of psychometric properties, the appropriateness of using a given global scale in a drug trial. Reported reliability and validity estimates for the aforementioned scales range from fair to very good, but small sample sizes and/or inappropriate measures of correlation weaken the quality of the evidence. There is also a dearth of published information on responsiveness to change. Researchers planning AD drug trials should consider these issues, along with the interval between test administrations for test-retest reliability, to help select appropriate global outcome measurement instruments.

Review of outcome measurement instruments in Alzheimer's disease drug trials: introduction

This article introduces a four-part series on outcome scales used in Alzheimer's disease drug trials. First, it discusses the division of scales into four domains: cognition, functional ability/quality of life, behavior/mood, and global. Within each domain, the shortcomings of existing literature reviews are outlined, and the need for a more coherent view of the psychometric properties of the scales is emphasized. Second, the key concepts of reliability, validity, and responsiveness to change are defined and explained. This explanation also provides an overview of the statistical techniques used to assess measurement properties. Finally, the methods used to select the scales for review in the subsequent articles are explained, and each article is briefly introduced.

Review of outcome measurement instruments in Alzheimer's disease drug trials: psychometric properties of behavior and mood scales

This article reviews the reliability and validity of eight scales for behavior and mood problems that were identified in a comparative analysis of Alzheimer's disease (AD) drug trials. The scales are the Brief Psychiatric Rating Scale, the Alzheimer's Disease Assessment Scale-noncognitive, the Relative's Assessment of Global Symptomatology, the Consortium to Establish a Registry for Alzheimer's Disease-Behavior Rating Scale for Dementia, the Dementia Behavior Disturbance scale, the Neuropsychiatric Inventory, and two scales for depressive symptoms, the Cornell Scale for Depression in Dementia and the Dementia Mood Assessment Scale. This article also examines methodological limitations in the way the published literature has assessed the psychometric properties of these scales. The aim is to help clinicians and potential trial investigators select appropriate measurement instruments with which to assess behavior and mood problems in AD and to assist AD researchers in the evaluation of the psychometric properties of such scales.

Review of outcome measurement instruments in Alzheimer's disease drug trials: psychometric properties of functional and quality of life scales

The psychometric properties of functional and quality of life outcome measures that were used for the purpose of showing changes in antidementia drug trials for Alzheimer's disease are described and critiqued. The seven functional scales reviewed for reliability, validity, and responsiveness to change included the Geriatric Evaluation by Relative's Rating Instrument, the Physical Self-Maintenance Scale, the Instrumental Activities of Daily Living, the Blessed Dementia Scale, Part 1 and its revised version, the Interview for Deterioration in Daily Living with Dementia, the Unified Activities of Daily Living, and the Dependence Scale. The Progressive Deterioration Scale and Quality of Life Assessment were classified as quality of life scales. The majority of the scales were found to exhibit serious limitations, such as incomplete reliability and validity assessment for the intended uses. The most pervasive problem was a lack of data on responsiveness to change. It is recommended that further research be conducted to develop new tools or enhance existing measures for the assessment of both quality of life and functional ability.

Tissue-specific synthesis and oxidative metabolism of estrogens

Estrogen exposure represents the major known risk factor for development of breast cancer in women and is implicated in the development of prostate cancer in men. Human breast tissue has been shown to be a site of oxidative metabolism of estrogen due to the presence of specific cytochrome P450 enzymes. The oxidative metabolism of 17beta-estradiol (E2) to E2-3,4-quinone metabolites by an E2-4-hydroxylase in breast tissue provides a rational hypothesis to explain the mammary carcinogenic effects of estrogen in women because this metabolite is directly genotoxic and can undergo redox cycling to form genotoxic reactive oxygen species. In this chapter, evidence in support of this hypothesis and of the role of P4501B1 as the 4-hydroxylase expressed in human breast tissue is reviewed. However, the plausibility of this hypothesis has been questioned on the grounds that insufficient E2 is present in breast tissue to be converted to biologically significant amounts of metabolite. This critique is based on the assumption that plasma and tissue E2 levels are concordant. However, breast cancer tissue E2 levels are 10-fold to 50-fold higher in postmenopausal women than predicted from plasma levels. Consequently, factors must be present to alter breast tissue E2 levels independently of plasma concentrations. One such factor may be the local production of E2 in breast tissue through the enzyme aromatase, and the evidence supporting the expression of aromatase in breast tissue is also reviewed in this chapter. If correct, mutations or environmental factors enhancing aromatase activity might result in high tissue concentrations of E2 that would likely be sufficient to serve as substrates for CYP1B1, given its high affinity for E2. This concept, if verified experimentally, would provide plausibility to the hypothesis that sufficient E2 may be present in tissue for formation of catechol metabolites that are estrogenic and which, upon further oxidative metabolism, form genotoxic species at levels that may contribute to estrogen carcinogenesis.

[Utilization of lifting equipment and slings in occupational therapy]

The occupational therapist is frequently involved in the allocation process of lifting devices for clients with severe physical disabilities who are living in the community. The aim of this paper is to introduce a conceptual framework to help therapists prescribe lifting devices, including the slings. First, factors influencing the decision to prescribe such an aid are analysed based on the concepts of the Canadian Model of Occupational Performance (Canadian Association of Occupational Therapists, 1997). When working with clients toward maximizing their transfer skills, occupational therapists will take into account different aspects such as the characteristics of the client, the environment and the equipment, as well as the time allocated to complete the activity. Secondly, the notion of the work situation outlined by an organization specializing in work safety measures is used as a guide for transfer evaluation. From this viewpoint, the introduction of the lifting device occurs along a continuum of progressive loss of independence and is determined by degrees of personal independence, human assistance as well as technical assistance required to perform transfers. Finally, advantages and disadvantages of using lifting devices in a home setting are presented as a conclusion to the study.

Markers of bone resorption in patients treated with pamidronate

Pyridinoline (PYD), deoxypyridinoline (DPD), and N-telopeptide (NTX) are markers of bone resorption. In cancer patients with bone metastases, NTX is more often elevated than either of the pyridinolines. Bisphosphonates inhibit osteoclasts and their treatment decreases skeletal complications of malignancy. The aim of this study was to correlate urinary PYD, DPD, and NTX levels with clinical events in patients receiving pamidronate. 25 cancer patients with lytic bone disease were treated with monthly pamidronate combined with endocrine or chemotherapy; 27 others were on placebo. Twenty-four hour urines were collected at baseline, 1, 3 and 6 months. NTX values were determined by enzyme-linked immunosorbent assay (ELISA); PYD and DPD values were determined by reverse phase high performance liquid chromatography (HPLC). Two hour urines were also collected weekly for 21 patients. The greatest difference as a result of pamidronate treatment was observed in NTX values. Maximum suppression was achieved 2 weeks after treatment. Of the 25 patients who received pamidronate, 21 had initially elevated NTX values. 12 of the 21 finished with normal NTX values, whilst 9/21 had NTX values which remained abnormally elevated. The proportions of patients with fractures between these two subgroups approached statistical significance (P = 0.07) while the proportions with bony disease progression were significant (P = 0.03, Fisher's exact test). Measuring NTX levels appears useful in monitoring bisphosphonate therapy of bone metastases. The goal of treatment should be to normalise NTX excretion.

Diversity of pubertal testosterone changes in boys with constitutional delay in growth and/or adolescence

In a group of 22 boys with constitutional delay in growth and/or adolescence, intermittent testosterone enanthate treatment was employed in a randomized clinical trial at multiple doses ranging from 25-100 mg every two weeks for three month periods extending over 15-21 months. Twelve of the patients displayed a prompt increase in endogenous testosterone levels during the study period, reaching levels in the adult male range (> 250 ng/dl). The remaining 10 boys showed sluggish changes in endogenous testosterone during the investigation, ranging from 35-177 ng/dl. The bone ages and testicular sizes of the two groups at study initiation did not differ though urine LH was significantly less at study entry in the slowly maturing group. The data reveal a great diversity in the pace and pattern of endogenous testosterone changes in the study population. The results also suggest that exogenous sex steroid treatment of such patients does not speed up the central nervous system processes controlling the onset and progression of puberty. Boys with delayed puberty should be followed until endogenous testosterone levels reach the adult male range in order to rule out mild gonadotropin deficits.

Induction of a less aggressive breast cancer phenotype by protein kinase C-alpha and -beta overexpression

To address the isoenzyme-specific involvement of protein kinase C (PKC) in breast cancer biology, hormone-responsive MCF-7 breast cancer cells were infected with either PKC-alpha or -beta 1 cDNAs subcloned in the retroviral expression vector pMV7. Several stable clones of PKC-overexpressing cells were generated. Western analysis revealed cross-regulation between the alpha and beta isoforms, because induction of overexpression of one up-regulated the other. Overexpression of the alpha and beta isoenzymes, on the other hand, did not affect the already high endogenous expression of the novel delta, epsilon, eta, and zeta isoforms. Compared with control clones, PKC-alpha- and -beta-overexpressing MCF-7 cells exhibited more drastic morphological changes in response to phorbol 12-myristate 13-acetate administration characterized by cellular flattening and vacuolization. More importantly, induction of PKC-alpha and -beta overexpression induced a less aggressive biological behavior, which was characterized by reduced in vitro invasiveness and markedly diminished tumor formation and growth in nude mice. These in vivo findings can probably best be explained by the dramatic down-regulation of estrogen receptor levels observed in tumors derived from PKC-alpha-infected MCF-7 cells. Our data clearly show that it is possible to induce a less aggressive breast cancer phenotype by altering PKC isoenzyme expression.

Serial serum c-erbB-2 levels in patients with breast carcinoma

BACKGROUND

Recently, the extracellular domain of the c-erbB-2 oncogene product (HER-2/neu) has been reported to be elevated in the serum of one-fourth of patients with metastatic breast carcinoma. The role of serum c-erbB-2 as a tumor marker, however, is still poorly defined. The purpose of this study was to evaluate the utility of serial serum c-erbB-2 levels as a tumor marker in patients with metastatic breast carcinoma.

METHODS

c-erbB-2 levels in the sera of patients with breast carcinoma were determined by an enzyme immunoassay that detects the extracellular domain of c-erbB-2. Serum c-erbB-2 levels were evaluated prior to treatment as well as throughout the course of treatment with second-line hormonal therapy employing either megestrol acetate or fadrozole, an experimental aromatase inhibitor.

RESULTS

Fifty-eight of 300 patients (19.3%) had elevated pretreatment serum c-erbB-2 levels. Of these 58 patients with elevated pretreatment c-erbB-2, 48 had more than 1 visit which enabled us to quantitate serial c-erbB-2 levels throughout the course of treatment. Of these 48 patients, 28 (58.3%) had serial c-erbB-2 values that correlated with the clinical course.

CONCLUSIONS

Serial serum c-erbB-2 levels did not show a high overall correlation with the clinical course in this group of patients with metastatic breast carcinoma treated with second-line hormonal therapy.

Development of the Quebec User Evaluation of Satisfaction with assistive Technology (QUEST)

This study's purpose was to develop a clinical instrument designed to evaluate user satisfaction with assistive technology devices. This paper describes the methodology used to develop the instrument entitled the Quebec User Evaluation of Satisfaction with assistive Technology (QUEST). Based on the theoretical and practical foundations of assistive technology as well as on the concept of satisfaction, preliminary versions of the instrument were created and examined by a panel of team participants. After the panel's recommendations were incorporated, a pretest of the revised instrument was conducted and the final French version of QUEST emerged. The originality of QUEST lies in its inter-activeness and user-directed approach to assessing satisfaction with assistive technology. From a set of 27 variables, the user is asked to indicate the degree of importance he/she attributes to each of the satisfaction variables and then to rate his/her degree of satisfaction with each of the variables considered (quite or very) important. While QUEST remains a clinical instrument undergoing pilot testing, it holds much promise in our quest for a reliable and valid means of assessing assistive technology outcome from the user's perspective.

Isolation and characterization of human breast cancer cells overexpressing S-adenosylmethionine decarboxylase

We report the first successful isolation and initial characterization of S-adenosylmethionine decarboxylase (SAMDC)-overexpressing cells using a transfection approach. Stably transfected MCF-7 breast cancer overproducing SAMDC (approximately 5-fold) manifested reduced ornithine decarboxylase while levels of N'-spermidine/spermine acetyltransferase were variably increased. Analysis of cellular polyamine profile showed that spermine was selectively increased (approximately 80%), while spermidine and putrescine levels were reduced (approximately 48% and approximately 15% of control, respectively). Since SAMDC-overexpressing clones exhibited increased clonogenicity in soft agar, our data suggest that spermine may be selectively involved in conferring a more invasive phenotype to breast cancer cells.

Biochemical and growth-modulatory effects of the new S-adenosylmethionine decarboxylase inhibitor CGP 48664 in malignant and immortalized normal human breast epithelial cells in culture

CGP 48664 [4-aminoindanon-1-(2'-amidino)hydrazone dihydrochloride monohydrate] is a newly introduced inhibitor of S-adenosylmethionine decarboxylase (SAMDC) with increased selectivity of action and reduced toxicity. We analyzed the biochemical and antiproliferative effects of this compound in a panel of hormone-dependent (3 clones of MCF-7, T47D) and -independent (MDA-MB-231, BT-20) human breast cancer cell lines in culture. For comparison, we also tested its effects in the spontaneously immortalized human breast epithelial cell line MCF-10A. All cell lines were highly sensitive to the growth-inhibitor effect of CGP 48664 with an IC50 between 0.1 and 0.5 microM. A dose-dependent bell-shaped increase in SAMDC was observed in normal and malignant breast cells resulting from enzyme stabilization by the inhibitor as supported by Western blot analysis. While ornithine decarboxylase (ODC) activity consistently increased, the effect of CGP 48664 on spermidine/spermine N'acetyltransferase (SSAT) was variable in the breast cancer cell lines. In contrast, the inhibitor consistently reduced SSAT activity level in the MCF-10A cell line and its derivative partially transformed by a mutated ras oncogene. As expected cellular putrescine levels were markedly increased by CGP 48664 administration, whereas spermidine and spermine contents were reduced. However, the degree of reduction was usually only moderate. Furthermore, exogenous polyamine administration was relatively ineffective in rescuing the antiproliferative effect of CGP 48664 in MCF-7 cells, while exerting a more complete rescue in the MDA-MB-231 cell line. We conclude that CGP 48664 exerts a potent growth-inhibitory effect on mammary cells in culture. However, its action may not always be entirely mediated through the polyamine pathway.

ARIMIDEX: a new oral, once-a-day aromatase inhibitor

ARIMIDEX is a potent and selective aromatase inhibitor undergoing evaluation as a treatment for postmenopausal women with advanced breast cancer. Studies examining the pharmacology of ARIMIDEX were conducted in both animals and humans. In animals, ARIMIDEX elicits maximal aromatase suppressive activity at a dose of approx. 0.1 mg/kg, does not alter adrenal steroid hormone biosynthesis, and at a dose of 1 mg/kg, has no other pharmacologic effects other than aromatase inhibition. In this overview, the pharmacodynamic, pharmacokinetic, and safety profiles of single and multiple daily doses of ARIMIDEX are reported in humans. Daily doses of 1-10 mg of ARIMIDEX suppressed estradiol levels to the maximum degree measurable using sensitive estrogen assays. ARIMIDEX had no clinically significant effects on the response of cortisol and aldosterone to ACTH stimulation. Absorption of ARIMIDEX was rapid, with maximum plasma concentrations occurring within 2 h after oral administration. Plasma concentrations of ARIMIDEX rose with increasing doses of the drug. The elimination half-life of ARIMIDEX in humans ranged from 30 to 60 h. Consistent with the long plasma half-life, steady state plasma concentrations were 3-4-fold higher than plasma concentrations observed after single administration of 1, 3, 5, or 10 mg doses. Long term treatment of breast cancer patients with 10 mg/day has continued in 17 patients without an escape of estradiol suppression. Previously, these patients had received on average 2.6 systemic treatments for breast cancer and had significant metastatic disease. Three of the 17 patients continued ARIMIDEX treatment for 20 months and beyond. Given the number of previous treatments and tumor burden at the start of treatment, the response to ARIMIDEX treatment is encouraging. Phase III studies are now underway to assess the efficacy and safety of ARIMIDEX in the treatment of advanced breast cancer.

Elevated serum c-erbB-2 antigen levels and decreased response to hormone therapy of breast cancer

PURPOSE

Decisions concerning the use of hormone therapy to treat metastatic breast cancer are made on the basis of the presence of estrogen receptor (ER). Despite the presence of ER, half of patients will not respond to hormone treatment. The purpose of this study was to determine the effect of overexpression of HER-2/neu on the response to hormone therapy.

PATIENTS AND METHODS

Sera from 300 metastatic breast cancer patients with ER-positive (ER+), ER status unknown, or ER-/progesterone receptor-positive (PR+) randomized to receive second-line hormone therapy with either megestrol acetate or fadrozole were evaluated. An enzyme immunoassay (EIA) specific for the extracellular domain of the c-erbB-2 (HER-2/neu) oncogene product was used to detect serum levels.

RESULTS

Fifty-eight patients (19.3%) had elevated serum c-erbB-2 protein levels, using a selected cut-point of 30 U/mL. The response rate (complete responses [CRs] plus partial responses [PRs] plus stable disease [S]) to endocrine therapy was 40.9% in 242 patients with low serum c-erbB-2 levels and only 20.7% in 58 patients with elevated serum c-erbB-2 levels (P = .004). The median duration of treatment response was longer in the group with low serum c-erbB-2 levels (15.5 months) compared with the group with elevated serum c-erbB-2 levels (11.6 months). Survival was also significantly shorter in patients with elevated serum c-erbB-2 levels (P < .0001).

CONCLUSION

Patients with ER+/c-erbB-2+ metastatic breast cancer are less likely to respond to hormone treatment than ER+/c-erbB-2- patients. Their survival duration is also shorter.

Phenotypic features of breast cancer cells overexpressing ornithine-decarboxylase

Polyamines (PA) have been shown to be critical mediators of estradiol-induced breast cancer cell proliferation. This finding suggests that constitutive activation of the PA pathway may promote tumor progression, possibly leading to hormone independence. To test this hypothesis, we transfected hormone-responsive MCF-7 breast cancer cells with a complementary DNA coding for ornithine-decarboxylase (ODC), the first rate-limiting enzyme in PA biosynthesis. Marked ODC overexpression observed in stably transfected clones was associated with a selective increase in cellular putrescine content, while spermidine and spermine levels were not altered. ODC-overexpressing MCF-7 cells were resistant to the antiproliferative effects of low but not high concentrations of the enzyme inhibitor, alpha-difluoromethylornithine. In agreement with our hypothesis, sensitivity to the growth-promoting action of estradiol was reduced by approximately one third (P < 0.001) in ODC-overexpressing MCF-7 cells compared with vector-only transfected clones. Basal growth under anchorage-dependent conditions was only marginally increased by ODC overexpression (P = 0.048), while clonogenicity in soft agar was actually reduced. These data suggest that activation of PA biosynthesis may contribute in part to the acquisition of estrogen independence by breast cancer cells. Since only putrescine content was increased as a result of ODC overexpression, these data may underestimate the overall influence of the PA pathway on breast cancer phenotype.

Polyamine profiles and growth properties of ornithine decarboxylase overexpressing MCF-7 breast cancer cells in culture

To determine the direct influence of the polyamine (PA) pathway on breast cancer phenotype, we employed a transfection approach to induce overexpression of the PA biosynthetic enzyme ornithine decarboxylase (ODC) in the hormone-responsive MCF-7 breast cancer cell line. Using a modified calcium phosphate method and an ODC cDNA coding for a truncated and more stable enzyme, we were able to achieve a moderate to marked degree of ODC overexpression (up to 150-fold) in a transient transfection system. ODC-overexpressing MCF-7 cells exhibited a selective increase in cellular putrescine content, while the levels of spermidine and spermine remained unaffected. Under defined culture conditions, overexpression of ODC resulted in a consistent but modest increase in [3H]thymidine incorporation into DNA which was similar in the presence and absence of 17-beta-estradiol, TGF-alpha, and IGF-I. In the presence of serum, the effect of ODC overexpression on basal [3H]-thymidine incorporation into DNA was inconsistent, possibly as a result of subtle differences in culture conditions. Overall, our results support the hypothesis that activation of the PA biosynthetic pathway may confer a growth advantage to breast cancer cells.

Calcium absorption, endogenous excretion, and endocrine changes during and after long-term bed rest

Negative calcium balance is a known consequence of bed rest, and is manifested in elevated urine and fecal calcium (Ca). Elevated fecal Ca can result from either decreased absorption, increased endogenous fecal excretion, or both. We measured the Ca absorption and endogenous fecal excretion in eight healthy male volunteers before and during 4 months of bed rest. Dual isotope (n = 6) or single isotope (n = 2) methods in conjunction with Ca balance were used to calculate true and net Ca absorption and endogenous fecal excretion. Stool Ca increased from 797 mg/day (mean intake 991 mg/day) to 911 mg/day during bed rest, whereas urine Ca excretion increased from 174 to 241 mg/day. True Ca absorption decreased from 31 +/- 7% of Ca intake pre-bed rest to 24 +/- 2% during bed rest, (p < 0.05) and returned toward pre-bed rest values within 5-6 weeks following reambulation. Endogenous fecal excretion did not change significantly, and therefore, most of the increased fecal Ca resulted from changes in absorption. However, in one individual, endogenous fecal Ca excretion was the major contributor to Ca loss. Ionized Ca and pyridinium crosslinks increased and 1,25(OH)2 vitamin D decreased during bed rest, similar to the decrease in Ca absorption; parathyroid hormone (PTH), calcitonin, serum albumin, phosphorus, and total serum Ca were unchanged. Although alkaline phosphatase, osteocalcin, and PTH were unchanged during bed rest, they were elevated during reambulation. These changes accompanied by increased Ca absorption and balance and decreased ionized and total serum Ca suggest a rebound in bone formation following immobilization.

Usefulness of sequential urinary follicle-stimulating hormone and luteinizing hormone measurements in the diagnosis of adolescent hypogonadotropism in males

FSH and/or LH deficiency in the second decade of life remains difficult to diagnose with testing at a single point in time because of the partial lack of hormone as well as the dynamic and inherently variable aspects of the pubertal process. A longitudinal study of gonadotropin excretion, therefore, was carried out in 78 normal boys and 157 male patients, aged 10-28 yr, with relative or absolute deficiencies of FSH and/or LH. Seven hundred and fifty-five timed urine samples were extracted with acetone, concentrated, and subjected to RIA. The results from patient groups with multiple tropic hormone deficiencies or isolated gonadotropin deficiency were clearly different from those of normal boys and individuals with constitutional delay in puberty. However, multiple samples obtained over a 2-yr period and, in selected cases, until the late teenage years may be required to diagnose gonadotropin deficiency in some patients, even using stringent predictive modeling criteria.

Increased urinary excretion of pyridinium cross-links in cancer patients

Pyridinoline (PYD) and deoxypyridinoline (DPD), two collagen-based cross-links found in bone, were measured by high-performance liquid chromatography in urine samples from 65 control subjects and 97 patients with either untreated or progressive cancer. Patients with cancer had significantly (P < 0.001) higher urine concentrations of PYD and DPD than did control subjects. Both cross-links were increased in cancer patients with and without clinically detectable bone metastases, although patients with bone and liver involvement had higher mean concentrations. The mean concentrations of both cross-links were also significantly higher in the urine samples of inpatients than in an outpatient ambulatory population. These findings suggest that the measurement of PYD and DPD in urine may be useful in assessing bone metastases and bone resorption in cancer patients.

Increased urinary excretion of pyridinium cross-links in cancer patients

Pyridinoline (PYD) and deoxypyridinoline (DPD), two collagen-based cross-links found in bone, were measured by high-performance liquid chromatography in urine samples from 65 control subjects and 97 patients with either untreated or progressive cancer. Patients with cancer had significantly (P &lt; 0.001) higher urine concentrations of PYD and DPD than did control subjects. Both cross-links were increased in cancer patients with and without clinically detectable bone metastases, although patients with bone and liver involvement had higher mean concentrations. The mean concentrations of both cross-links were also significantly higher in the urine samples of inpatients than in an outpatient ambulatory population. These findings suggest that the measurement of PYD and DPD in urine may be useful in assessing bone metastases and bone resorption in cancer patients.