Mapping the Ecological Terrain of Stroke Prehospital Delay: A Nationwide Registry Study

BACKGROUND

Delays in hospital presentation limit access to acute stroke treatments. While prior research has focused on patient-level factors, broader ecological and social determinants have not been well studied. We aimed to create a geospatial map of prehospital delay and examine the role of community-level social vulnerability.

METHODS

We studied patients with ischemic stroke who arrived by emergency medical services in 2015 to 2017 from the American Heart Association Get With The Guidelines-Stroke registry. The primary outcome was time to hospital arrival after stroke (in minutes), beginning at last known well in most cases. Using Geographic Information System mapping, we displayed the geography of delay. We then used Cox proportional hazard models to study the relationship between community-level factors and arrival time (adjusted hazard ratios [aHR] <1.0 indicate delay). The primary exposure was the social vulnerability index (SVI), a metric of social vulnerability for every ZIP Code Tabulation Area ranging from 0.0 to 1.0.

RESULTS

Of 750 336 patients, 149 145 met inclusion criteria. The mean age was 73 years, and 51% were female. The median time to hospital arrival was 140 minutes (Q1: 60 minutes, Q3: 458 minutes). The geospatial map revealed that many zones of delay overlapped with socially vulnerable areas (https://harvard-cga.maps.arcgis.com/apps/webappviewer/index.html?id=08f6e885c71b457f83cefc71013bcaa7). Cox models (aHR, 95% CI) confirmed that higher SVI, including quartiles 3 (aHR, 0.96 [95% CI, 0.93-0.98]) and 4 (aHR, 0.93 [95% CI, 0.91-0.95]), was associated with delay. Patients from SVI quartile 4 neighborhoods arrived 15.6 minutes [15-16.2] slower than patients from SVI quartile 1. Specific SVI themes associated with delay were a community's socioeconomic status (aHR, 0.80 [95% CI, 0.74-0.85]) and housing type and transportation (aHR, 0.89 [95% CI, 0.84-0.94]).

CONCLUSIONS

This map of acute stroke presentation times shows areas with a high incidence of delay. Increased social vulnerability characterizes these areas. Such places should be systematically targeted to improve population-level stroke presentation times.

Characterizing Trauma Patients with Delays in Orthopaedic Process Measures

INTRODUCTION

Early operative intervention in orthopaedic injuries is associated with decreased morbidity and mortality. Relevant process measures (e.g. femoral shaft fixation <24 hours) are used in trauma quality improvement programs to evaluate performance. Currently, there is no mechanism to account for patients who are unable to undergo surgical intervention (i.e. physiologically unstable). We characterized the factors associated with patients who did not meet these orthopaedic process measures.

METHODS

A retrospective cohort study of patients from 35 ACS-COT verified Level 1 and Level 2 trauma centers was performed utilizing quality collaborative data (2017-2022). Inclusion criteria were adult patients (≥18 years), ISS ≥5, and a closed femoral shaft or open tibial shaft fracture classified via the Abbreviated Injury Scale version 2005 (AIS2005). Relevant factors (e.g. physiologic) associated with a procedural delay >24 hours were identified through a multivariable logistic regression and the effect of delay on inpatient outcomes was assessed. A sub-analysis characterized the rate of delay in "healthy patients".

RESULTS

We identified 5,199 patients with a femoral shaft fracture and 87.5% had a fixation procedure, of which 31.8% had a delay, and 47.1% of those delayed were "healthy." There were 1,291 patients with an open tibial shaft fracture, 92.2% had fixation, 50.5% had an irrigation and debridement and 11.2% and 18.7% were delayed, respectively. High ISS, older age and multiple medical comorbidities were associated with a delay in femur fixation, and those delayed had a higher incidence of complications.

CONCLUSIONS

There is a substantial incidence of surgical delays in some orthopaedic trauma process measures that are predicted by certain patient characteristics, and this is associated with an increased rate of complications. Understanding these factors associated with a surgical delay, and effectively accounting for them, is key if these process measures are to be used appropriately in quality improvement programs.

LEVEL OF EVIDENCE

Level III; Therapeutic/Care Management.

The Trauma Dyad: The Role of Informal Caregivers for Older Adults After Traumatic Injury

OBJECTIVE

To investigate the association between higher injury severity and increased informal caregiving received by injured older adults.

SUMMARY OF BACKGROUND DATA

Injured older adults experience high rates of functional decline and disability after hospitalization. Little is known about the scope of caregiving received post-discharge, particularly from informal caregivers such as family.

METHODS

We used the National Health and Aging Trends Study 2011 to 2018 linked to Medicare claims to identify adults ≥65 with hospital admission for traumatic injury and a National Health and Aging Trends Study interview within 12 months pre- and post-trauma. Injury severity was assessed using the injury severity score (ISS, low 0-9; moderate 10-15; severe 16-75). Patients reported the types and hours of formal and informal help received and any unmet care needs. Multi variable logistic regression models examined the association between ISS and increase in informal caregiving hours after discharge.

RESULTS

We identified 430 trauma patients. Most were female (67.7%), non-Hispanic White (83.4%) and half were frail. The most common mechanism of injury was fall (80.8%) and median injury severity was low (ISS = 9). Those reporting receiving help with any activity increased post-trauma (49.0% to 72.4%, P < 0.01), and unmet needs nearly doubled (22.8% to 43.0%, P < 0.01). Patients had a median of 2 caregivers and most (75.6%) were informal, often family members. Median weekly hours of care received pre- versus post-injury increased from 8 to 14 (P < 0.01). ISS did not independently predict increase in caregiving hours; pre-trauma frailty predicted an increase in hours ≥8 per week.

CONCLUSIONS

Injured older adults reported high baseline care needs which increased significantly after hospital discharge and were mostly met by informal caregivers. Injury was associated with increased need for assistance and unmet needs regardless of injury severity. These results can help set expectations for caregivers and facilitate post-acute care transitions.

Developing a National Trauma Research Action Plan: Results from the geriatric research gap Delphi survey

BACKGROUND

Treating older trauma patients requires a focus on the confluence of age-related physiological changes and the impact of the injury itself. Therefore, the primary way to improve the care of geriatric trauma patients is through the development of universal, systematic multidisciplinary research. To achieve this, the Coalition for National Trauma Research has developed the National Trauma Research Action Plan that has generated a comprehensive research agenda spanning the continuum of geriatric trauma care from prehospital to rehabilitation.

METHODS

Experts in geriatric trauma care and research were recruited to identify current gaps in clinical geriatric research, generate research questions, and establish the priority of these questions using a consensus-driven Delphi survey approach. Participants were identified using established Delphi recruitment guidelines ensuring heterogeneity and generalizability. On subsequent surveys, participants were asked to rank the priority of each research question on a nine-point Likert scale, categorized to represent low-, medium-, and high-priority items. The consensus was defined as more than 60% of panelists agreeing on the priority category.

RESULTS

A total of 24 subject matter experts generated questions in 109 key topic areas. After editing for duplication, 514 questions were included in the priority ranking. By round 3, 362 questions (70%) reached 60% consensus. Of these, 161 (44%) were high, 198 (55%) medium, and 3 (1%) low priority.

CONCLUSION

Among the questions prioritized as high priority, questions related to three types of injuries (i.e., rib fracture, traumatic brain injury, and lower extremity injury) occurred with the greatest frequency. Among the 25 highest priority questions, the key topics with the highest frequency were pain management, frailty, and anticoagulation-related interventions. The most common types of research proposed were interventional clinical trials and comparative effectiveness studies, outcome research, and health care systems research.

Influences on the dietary intakes of preschool children: a systematic scoping review

Background

Better diet quality of preschool children is associated with many important health outcomes, but there is significant room for improvement in many children’s dietary intakes. The determinants of children’s dietary intakes are complex and whole systems approaches may be effective tools for changing dietary intake. Collation of all the evidence available on determinants of preschool children’s dietary intake is necessary to ‘map’ the whole system of influence. Therefore, this systematic scoping review of available literature on determinants of dietary intakes in preschool children was undertaken.

Methods

The Joanna Briggs Institute methods for conducting a systematic scoping review were followed. Articles published since 2000 which assessed influences on the dietary intakes of preschool children were identified, yielding a total of 246 papers. Studies of children with clinical conditions (excluding obesity), or those conducted in middle and low-income countries were excluded, due to the different systems of influence in these populations. Data were extracted and information synthesised based on ecological level (child, parent, household, childcare, or wider determinants).

Results

Most articles focused on influences at the parental level (n = 118, 48%), followed by those at the child level (n = 73, 30%). Most of the studies were of cross-sectional design (n = 109, 44%). Whilst many studies considered influences at multiple ecological levels (n = 63, 26%) few analyses determined interactions between factors in their relationship with children’s dietary intakes, which is needed going forward using systems methods.

Conclusion

A wealth of evidence exists examining influences on the dietary intakes of preschool children and this information would benefit from analysis using a systems thinking approach in order to assess effective levers for intervention and what works, for whom, under what circumstances.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12966-022-01254-8.

Abstract P133: Geospatial Mapping of Prehospital Delay in Acute Ischemic Stroke and Association With Social Vulnerability

Introduction: Prehospital delay, defined as the delay between symptom discovery and hospital arrival, remains a major barrier to timely acute stroke treatments. Delay is worse in socially vulnerable populations. A geospatial map of prehospital delay may identify high-risk areas and highlight the role of community social vulnerability in delay. We hypothesized that a community’s social vulnerability would be associated with delay.

Methods: We analyzed national Get With The Guidelines ischemic stroke data between 2015 and 2017. We calculated the median arrival time (symptom discovery-to-door times) for each Zip Code Tabulation Area (ZCTA), and created geospatial map using ArcGIS. The primary exposure variable was the Center for Disease Control’s Social Vulnerability Index (SVI), and its 4 subcomponents. The SVI is a composite metric of community vulnerability using U.S. Census data (0, least vulnerable to 1, most vulnerable). To account for clustering within ZCTAs, we performed a multilevel linear regression of community-level SVI and patient-level prehospital delay.

Results: During the study period, 149,774 patients had an ischemic stroke in 16,949 ZCTAs. Across patients, the median time of arrival was 140 mins, IQR was 60-459 mins, and range was 1-1439 mins. Arrival by 2h occurred in 46% of patients. Multilevel regression showed a strong positive association between the SVI and prehospital delay, evident in the maps (Figure). For every 10% increase in the SVI, the arrival time increased by 38 minutes [CI, 30 - 47] (p<0.001). Considering the 4 SVI subcomponents, delay was most strongly associated with socioeconomic status, household composition, and housing/transportation, but not minority status/language.

Conclusion: Using geospatial mapping of prehospital delay across the United States, we show that community SVI is strongly associated with delayed ischemic stroke arrival. These maps help identify communities to target for stroke preparedness campaigns.

Sex differences in long-term outcomes after traumatic injury: A mediation analysis

BACKGROUND

We sought to examine the association and potential mediators between sex and long-term trauma outcomes.

METHODS

Moderately-to-severely injured patients admitted to 3 level-1 trauma centers were contacted between 6 and 12-months post-injury to assess for functional limitations, use of pain medications, and posttraumatic stress disorder (PTSD). Multivariable adjusted regression analyses were used to compare long-term outcomes by sex. Potential mediators of the relationship between sex and outcomes was explored using mediation analysis.

RESULTS

2607 patients were followed, of which 45% were female. Compared to male, female patients were more likely to have functional limitations (OR: 1.45; 95% CI: 1.31-1.60), take pain medications (OR: 1.17; 95% CI: 1.02-1.38), and screen positive for PTSD (OR: 1.60; 95% CI: 1.46-1.76) post-injury. Age, extremity injury, previous psychiatric illness, and pre-injury unemployment, partially mediated the effect of female sex on long-term outcomes.

CONCLUSIONS

There are significant sex differences in long-term trauma outcomes, which are partially driven by patient and injury-related factors.

Effectiveness of the American College of Surgeons Bleeding Control Basic Training Among Laypeople Applying Different Tourniquet Types: A Randomized Clinical Trial

Importance

More than 500 000 laypeople in the United States have been trained in hemorrhage control, including tourniquet application, under the Stop the Bleed campaign. However, it is unclear whether after hemorrhage control training participants become proficient in a specific type of tourniquet or can also use other tourniquets effectively.

Objective

To assess whether participants completing the American College of Surgeons Bleeding Control Basic (B-Con) training with Combat Application Tourniquets (CATs) can effectively apply bleeding control principles using other tourniquet types (commercial and improvised).

Design, Setting, and Participants

This nonblinded, crossover, sequential randomized clinical trial with internal control assessed a volunteer sample of laypeople who attended a B-Con course at Gillette Stadium and the Longwood Medical Area in Boston, Massachusetts, for correct application of each of 5 different tourniquet types immediately after B-Con training from April 4, 2018, to October 9, 2018. The order of application varied for each participant using randomly generated permutated blocks.

Interventions

Full B-Con course, including cognitive and skill sessions, that taught bleeding care, wound pressure and packing, and CAT application.

Main Outcomes and Measures

Correct tourniquet application (applied pressure of ≥250 mm Hg with a 2-minute time cap) in a simulated scenario for 3 commercial tourniquets (Special Operation Forces Tactical Tourniquet, Stretch-Wrap-and-Tuck Tourniquet, and Rapid Application Tourniquet System) and improvised tourniquet compared with correct CAT application as an internal control using 4 pairwise Bonferroni-corrected comparisons with the McNemar test.

Results

A total of 102 participants (50 [49.0%] male; median [interquartile range] age, 37.5 [27.0-53.0] years) were included in the study. Participants correctly applied the CAT at a significantly higher rate (92.2%) than all other commercial tourniquet types (Special Operation Forces Tactical Tourniquet, 68.6%; Stretch-Wrap-and-Tuck Tourniquet, 11.8%; Rapid Application Tourniquet System, 11.8%) and the improvised tourniquet (32.4%) (P < .001 for each pairwise comparison). When comparing tourniquets applied correctly, all tourniquet types had higher estimated blood loss, had longer application time, and applied less pressure than the CAT.

Conclusions and Relevance

The B-Con principles for correct CAT application are not fully translatable to other commercial or improvised tourniquet types. This study demonstrates a disconnect between the B-Con course and tourniquet designs available for bystander first aid, potentially stemming from the lack of consensus guidelines. These results suggest that current B-Con trainees may not be prepared to care for bleeding patients as tourniquet design evolves.

Trial Registration

ClinicalTrials.gov identifier: NCT03538379.

Variation in the Geographic Distribution of the Otolaryngology Workforce: A National Geospatial Analysis

Objective

To examine the current geographic distribution of otolaryngologists in the United States and the disparities in socioeconomic demographics at the county and hospital referral region (HRR) level.

Study Design

Cross-sectional study.

Setting

National cohort analysis including all otolaryngologists in the United States.

Subjects and Methods

All otolaryngologists board certified by the American Board of Otolaryngology–Head and Neck Surgery in the United States in 2018 were compared with overlaid demographic data from the 2010 United States Census Bureau by county and HRR. Associations between the density of otolaryngologists per population and socioeconomic characteristics were assessed and stratified by region.

Results

The average number of otolaryngologists was 3.6 (SD 9.6) per 100,000. On multivariable regression analysis, the density of otolaryngologists was positively associated with counties with the highest quartile of college education (1.8 providers per 100,000 [95% confidence interval [CI] 0.89, 2.90], P < .001) and income (2.1 providers per 100,000 [95% CI 1.03, 3.07], P = .01). Significant regional variation existed in access to otolaryngology care.

Conclusion

There are significant areas with disparate densities of otolaryngologists in the United States. Lower socioeconomic status, more severe poverty, and a lower number of college graduates in a county correlated with reduced density of otolaryngologists.

Point-of-care Hepatitis C virus testing and linkage to treatment in an Australian inner-city emergency department

BACKGROUND

In Australia, Hepatitis C Virus (HCV) treatment is declining, despite broad access to direct-acting antiviral medication. People who inject drugs are proportionally over-represented in emergency department presentations. Emergency department assessment of people who have injected drugs for HCV presents an opportunity to engage this marginalised population with treatment. We describe the outcomes of risk-based screening and point-of-care anti-HCV testing for emergency department patients, and linkage to outpatient antiviral treatment.

METHODS

During the three-month study period, consecutive adult patients who presented to the emergency department during the study times were screened for risk factors and offered the OraQuick oral HCV antibody test. Those with reactive results were offered venepuncture in the emergency department for confirmatory testing and direct-acting antiviral treatment in clinic. The main outcome measures were the number and proportion of viremic participants that were linked to the hepatitis clinic, commenced treatment and achieved a sustained viral response. Secondary outcome measures were the proportion (%) of presentations screened that were oral antibody reactive, and the prevalence and type of HCV risk factors.

RESULTS

During the study period, 2408 of the 3931 (61%) presentations to the emergency department were eligible for screening. Of these 2408 patients, 1122 (47%) participated, 307 (13%) declined participation and 977 (41%) could not be approached during their time in the emergency department. Among the 1122 participants, 378 (34%) reported at least one risk factor. Subsequently, 368 (97%) of the 378 participants underwent OraQuick anti-HCV test, and 50 (14%) had a reactive result. A risk factor of ever having injected drugs was present in 44 (88%) of participants who were sero-positive. Of the 45 that had blood tested, 30 (67%) were HCV ribonucleic acid (RNA) positive. Three participants died. Of the 27 remaining participants, 10 (37%) commenced treatment and 7 of these 10 (70%) obtained a cure. There was a high rate of homelessness (24%) among anti-HCV positive participants.

CONCLUSION

Among emergency department participants with a risk factor for HCV, positive serology was common using a rapid point-of-care test. A history of injecting drug use was identified as the risk factor with highest yield for positive HCV serology, and is suitable as a single screening question. However, linkage to care post ED presentation was low in this marginalised population. There is a need for new pathways to improve the care cascade for marginalised individuals living with HCV infection.

Colorectal Cancer in Ukraine: Regional Disparities and National Trends in Incidence, Management, and Mortality

Purpose

The incidence of colorectal cancer (CRC) is increasing worldwide, and the greatest increase is in low- to middle-income countries, such as Ukraine. Better knowledge of epidemiology of CRC in Ukraine is needed to understand how best to decrease the burden of disease.

Methods

The National Cancer Registry of Ukraine (NCRU) was queried for CRC incidence, mortality, stage, and treatment in Ukraine and assessed for regional variation from 1999 to 2015. Joinpoint analysis was used to analyze the trends.

Results

The incidence of colon cancer increased from 10.6 to 13.3 occurrences per 100,000, which provided an average annual percent change (AAPC) of 1.48 (95% CI, 1.3 to 1.7; P < .05). The incidence of rectal and anal cancers also increased from 9.9 to 11.5 occurrences per 100,000, which provided an AAPC of 1.0 (95% CI, 0.8 to 1.3; P < .05). Mortality remained the same (AAPC, 0.1; 95% CI, -0.3 to 0.2; P = .4). The proportion of patients who received cancer-specific treatment increased from 54.6% to 68.5% for colon cancer and from 61% to 74.4% for rectal and anal cancers. Overall, 34.5% of patients with colon cancer and 27.5% of patients with rectal cancer died within a year of diagnosis in 2015. Great regional variations in 1-year mortality and treatment received were identified.

Conclusion

The incidence of CRC in Ukraine is increasing. Despite stable mortality rates, many do not receive cancer-specific treatment, and a large proportion of patients die within a year of diagnosis. These findings illustrate the need to promote establishment of a screening program and to improve access to cancer-specific therapy in Ukraine.

The relationship between maternal self-efficacy, compliance and outcome in a trial of vitamin D supplementation in pregnancy

In a randomised controlled trial of vitamin D during pregnancy, we demonstrated that women with lower self-efficacy were more likely to experience practical problems with taking the trial medication and that this was associated with lower compliance and achieved 25(OH)-vitamin D concentrations.

INTRODUCTION

The relationship between self-efficacy (the belief that one can carry out a behaviour), compliance with study protocol and outcome was explored within a randomised, double-blind, placebo-controlled trial of vitamin D supplementation in pregnancy.

METHODS

In the Maternal Vitamin D Osteoporosis Study (MAVIDOS) trial, women with circulating plasma 25(OH)-vitamin D of 25-100 nmol/l in early pregnancy were randomised to either 1000 IU cholecalciferol/day or matched placebo from 14 weeks until delivery. Circulating 25(OH)-vitamin D concentrations were assessed at 14 and 34 weeks' gestation. A sequential sub-sample completed Schwarzer's General Self-Efficacy Scale at 14 and 34 weeks and the Problematic Experiences of Therapy Scale at 34 weeks. Women were interviewed about their experiences of the trial and interview transcripts analysed thematically.

RESULTS

In 203 women, those with higher self-efficacy were less likely to experience practical problems taking the study medication (odds ratio (OR) 0.81 (95 % confidence interval (CI) 0.69-0.95), p = 0.01). Over half reported practical problems associated with poorer compliance with the protocol requiring women to take the medication daily. Compliance in women who experienced practical problems was 94 % compared with 98 % for those with no problems (p < 0.001). Poorer compliance was also associated with lower concentrations of 25(OH)-D in late pregnancy in the treatment group (β = 0.54 nmol/l (95 % CI 0.18-0.89), p = 0.003). Thematic analysis suggested common difficulties were remembering to take the medication every day and swallowing the large capsules.

CONCLUSIONS

These findings suggest that differences in self-efficacy influence trial outcomes. Such information may help clinicians anticipate responses to routine vitamin D supplementation in pregnancy and identify those who may need more support to comply.

TRIAL REGISTRATION

ISRCTN82927713, registered 11/04/2008.

Low levels of food involvement and negative affect reduce the quality of diet in women of lower educational attainment

BACKGROUND

Women of lower educational attainment tend to have poorer quality diets and lower food involvement (an indicator of the priority given to food) than women of higher educational attainment. The present study reports a study of the role of food involvement in the relationship between educational attainment and quality of diet in young women.

METHODS

The first phase uses six focus group discussions (n = 28) to explore the function of food involvement in shaping the food choices of women of lower and higher educational attainment with young children. The second phase is a survey that examines the relationship between educational attainment and quality of diet in women, and explores the role of mediating factors identified by the focus group discussions.

RESULTS

The focus groups suggested that lower food involvement in women of lower educational attainment might be associated with negative affect (i.e. an observable expression of negative emotion), and that this might mean that they did not place a high priority on eating a good quality diet. In support of this hypothesis, the survey of 1010 UK women found that 14% of the effect of educational attainment on food involvement was mediated through the woman's affect (P ≤ 0.001), and that 9% of the effect of educational attainment on quality of diet was mediated through food involvement (P ≤ 0.001).

CONCLUSIONS

Women who leave school with fewer qualifications may have poorer quality diets than women with more qualifications because they tend to have a lower level of food involvement, partly attributed to a more negative affect. Interventions to improve women's mood may benefit their quality of diet.

Hormonal impact of the 17alpha-hydroxylase/C(17,20)-lyase inhibitor abiraterone acetate (CB7630) in patients with prostate cancer

A series of three dose escalating studies were conducted to investigate the ability of the 17α-hydroxylase/C_17,20-lyase inhibitor abiraterone acetate, to cause maximum suppression of testosterone synthesis when delivered to castrate and noncastrate males with prostate cancer. Study A was a single dose study in castrate males. Study B was a single dose study in noncastrate males and study C was a multiple dose study in noncastrate males. The drug was given orally in a once-daily dose and blood samples taken to assess pharmacokinetic (PK) parameters and hormone levels in all patients. The study drug was well tolerated with some variability in PKs. Suppression of testosterone levels to <0.14 nmol l⁻¹ was seen in four out of six castrate males treated with a single dose of 500 mg. At 800 mg given days 1–12 in noncastrate males, target suppression was achieved in three out of three patients, but a two- to three-fold increase of Luteinising Hormone (LH) levels in two out of three patients overcame suppression within 3 days. All patients in the multiple dose study developed an abnormal response to a short Synacthen test by day 11, although baseline cortisol levels remained normal. This is the first report of the use of a specific 17α-hydroxylase/_17,20-lyase inhibitor in humans. Repeated treatment of men with intact gonadal function with abiraterone acetate at a dose of 800 mg can successfully suppress testosterone levels to the castrate range. However, this level of suppression may not be sustained in all patients due to compensatory hypersecretion of LH. The enhanced testosterone suppression achieved in castrate men merits further clinical study as a second-line hormonal treatment for prostate cancer. Adrenocortical suppression may necessitate concomitant administration of replacement glucocorticoid.

A Cancer Research (UK) randomized phase II study of idoxifene in patients with locally advanced/metastatic breast cancer resistant to tamoxifen

Idoxifene is a novel selective oestrogen receptor modulator (SERM) which had greater binding affinity for the oestrogen receptor (ER) and reduced agonist activity compared with tamoxifen in preclinical studies. In a randomized phase II trial in 56 postmenopausal patients with progressive locally advanced/metastatic breast cancer we assessed whether idoxifene showed evidence of activity compared with an increased 40 mg/day dose of tamoxifen in patients who had previously demonstrated resistance to the standard 20 mg/day dose of tamoxifen. Of 47 patients eligible for response (25 idoxifene, 22 tamoxifen), two partial responses and two disease stabilizations (SD) for >6 months were seen with idoxifene (overall clinical benefit rate 16%, 95% CI 4.5-36.1%). The median duration of clinical benefit was 9.8 months. In contrast, no objective responses were seen with the increased 40 mg/day dose of tamoxifen, although two patients had SD for 7 and 14 months (clinical benefit rate 9%, 95% CI 1.1-29.2%). Idoxifene was well tolerated and the reported possible drug-related toxicities were similar in frequency to those with tamoxifen (hot flushes 13% vs 15%, mild nausea 20% vs 15%). Endocrine and lipid analysis in both groups showed a similar significant fall in serum follicle-stimulating hormone and luteinizing hormone after 4 weeks, together with a significant rise in sex hormone binding globulin levels and 11% reduction in serum cholesterol levels. In conclusion, while idoxifene was associated with only modest evidence of clinical activity in patients with tamoxifen-resistant breast cancer, its toxicity profile and effects on endocrine/lipid parameters were similar to those of tamoxifen.

Synthesis of certain 2'-deoxyuridine derivatives containing substituted phenoxy groups attached to C-5'; evaluation as potential dUTP analogues

Derivatives of 2'-deoxyuridine in which the 5'-OH group is replaced by a 2,3,6-trifluoro-5-hydroxy-4-nitrophenoxy or a 4-carboxy-2,3,6-trifluoro-5-hydroxyphenoxy group have been prepared for evaluation as possible dUTP analogues. They showed a weak ability to displace radiolabelled dUTP from a dUTP-binding antiserum. The corresponding compounds lacking the three fluorine substituents were prepared for comparison.

Unequal distribution of cognitive deficits in vascular dementia--is this a valid criterion in the ICD-10?

OBJECTIVE

To investigate the appropriateness of the ICD-10 criterion for vascular dementia which requires unequal distribution of deficits between different domains of cognitive function.

DESIGN

Cross-sectional comparative study.

SETTING

Referrals to a specialist memory clinic in Sheffield and a community sample of patients from a general practice population in Melton Mowbray.

METHOD

The CAMCOG part of the Cambridge mental disorders of the elderly examination (CAMDEX) was assessed for 131 Sheffield subjects and 396 Melton Mowbray subjects to examine both total variability and differences between individual subscale items. Depression was also examined as this was a potential confounding factor.

RESULTS

After adjustment for age, sex and depression scores, there were no significant differences between vascular dementia subjects and Alzheimer's disease subjects at either centre for total variability of cognitive deficits and little difference between diagnoses for individual subscale items. In Sheffield, subjects with vascular dementia had significantly higher depression scores compared to those with Alzheimer's disease.

CONCLUSIONS

The usefulness of the concept of unequal deficits as a diagnostic criterion for vascular dementia in routine clinical practice is doubtful.

Evaluating recovery from anorexia nervosa and bulimia nervosa: integrating lessons learned from research and clinical practice

The aims of this article are to critically examine the conceptualization and measurement of recovery, within the eating disorder outcome literature, and suggest possible ways of developing the clinical utility of outcome research. First, definitions and measures of recovery operationalized in outcome studies are critically reviewed, highlighting the variety of definitions and measures used in outcome research. Two important caveats in the outcome literature are identified: absence of clients' views on their recovery from outcome evaluations and dissociation of outcome research from negotiated interpersonal and organizational meanings of recovery. These caveats form the focus of the second section of the article. A need for greater integration between research and clinical perspectives on recovery is identified, and the final section of the article suggests several proposals for enhancing current research on recovery from eating disorders. These proposals particularly advocate development of methods and measures that can accommodate diversity of clients' experiences of recovery, while remaining informative to both researchers and clinicians.

Idoxifene antagonizes estradiol-dependent MCF-7 breast cancer xenograft growth through sustained induction of apoptosis

Idoxifene is a novel selective estrogen (E2) receptor (ER) modulator that is currently in clinical development for the treatment of breast cancer. Compared to tamoxifen, idoxifene is metabolically more stable, with a higher relative binding affinity for the ER and reduced agonist activity on breast and uterine cells. Idoxifene also inhibits calmodulin, a calcium-binding protein that is involved in cell signal transduction pathways. In this study, the abilities of idoxifene and tamoxifen to antagonize E2-dependent MCF-7 xenograft growth in oophorectomized athymic mice were compared. The basis for idoxifene's antitumor activity was examined by comparing the effectiveness of the clinically used transisomer (referred to here as idoxifene) with its cis-isomer, which has a 50-fold lower relative binding affinity for ER than idoxifene but similar calmodulin-inhibitory activity. Changes in tumor cell proliferation, apoptosis, and ER-dependent protein expression were studied. Both idoxifene and tamoxifen significantly inhibited E2-dependent tumor growth, whereas cis-idoxifene had little effect. Withdrawal of E2 support induced significant tumor regression due to impaired cell proliferation (Ki-67 score, 9 versus 51% compared to E2 controls) and induction of apoptosis (3.6 versus 0.9% compared to E2 controls). Both anti-E2s inhibited cell proliferation and caused a significant 3-fold induction of apoptosis in E2 supported tumors after 1 week, which was maintained for 3 months with idoxifene (3.1 versus 0.48% compared to E2 controls) but decreased back to baseline in tumors treated with tamoxifen (0.69%). In contrast, cis-idoxifene had no effect on either cell proliferation or apoptosis. Both tamoxifen and idoxifene initially induced ER expression, whereas prolonged therapy with tamoxifen significantly reduced progesterone receptor levels. In conclusion, idoxifene resulted in similar inhibition of E2-dependent MCF-7 xenograft growth compared with tamoxifen, an effect that is mediated via ER rather than through calmodulin. Sustained induction of apoptosis may contribute to prolonged antagonism of E2-dependent growth, and it occurred to a greater extent following 3 months of idoxifene, compared to tamoxifen.

Inhibition of protein prenylation by metabolites of limonene

The monoterpenes limonene and perillyl alcohol are undergoing clinical evaluation in cancer patients. In this paper, we report the chemical synthesis, characterisation, and quantitation in patients' plasma of a novel human metabolite of limonene, which is identified as an isomer of perillic acid. The synthesis of R-perillic acid is also described, because previous reports on the activity of perillic acid against isoprenylation enzymes refer to the S-enantiomer, although it is the R-enantiomer which is the metabolite of R-limonene. The above monoterpenes, with several related compounds, were assayed for inhibitory activity towards the isoprenylation enzymes in rat brain cytosol. Although R- and S-limonene are only weak inhibitors of the isoprenylation enzymes, their major metabolites, perillic acid and perillyl alcohol, are more potent inhibitors, with IC50 values in the low mM range. The metabolites possess greater activity towards the geranylgeranyltransferase type I enzyme than farnesyltransferase, while the novel metabolite displays IC50 values similar to those of perillic acid suggesting that it may contribute to the in vivo activity of limonene.

Solid-phase synthesis of novel inhibitors of farnesyl transferase

A novel diphosphate mimic, the 2,3,6-trifluoro-5-hydroxy-4-nitrophenoxy group (1), has been employed as the template in the solid-phase synthesis of novel farnesyl transferase inhibitors using the Mitsunobu reaction. The most potent inhibitor (farnesyloxy-5-hydroxy-2,3,6-trifluoro-4-nitrobenzene) displayed an IC50 of 6.3 microM versus farnesyl transferase.

The 16,17-double bond is needed for irreversible inhibition of human cytochrome p45017alpha by abiraterone (17-(3-pyridyl)androsta-5, 16-dien-3beta-ol) and related steroidal inhibitors

Abiraterone (17-(3-pyridyl)androsta-5,16-dien-3beta-ol, 1) is a potent inhibitor (IC50 4 nM for hydroxylase) of human cytochrome P45017alpha. To assist in studies of the role of the 16,17-double bond in its mechanism of action, the novel 17alpha-(4-pyridyl)androst-5-en-3beta-ol (5) and 17beta-(3-pyridyl)-16,17alpha-epoxy-5alpha-androst-3beta-ol (6) were synthesized. 3beta-Acetoxyetienic acid was converted in three steps into 5 via photolysis of the thiohydroxamic ester 8. Oxidation of an appropriate 16,17-unsaturated precursor (21) with CrO3-pyridine afforded the acetate (23) of 6. Inhibition of the enzyme by 1, the similarly potent 5,6-reduced analogue 19 (IC50 5 nM), and the 4, 16-dien-3-one 26 (IC50 3 nM) and by the less potent (IC50 13 nM) 3,5, 16-triene 25 is slow to occur but is enhanced by preincubation of the inhibitor with the enzyme. Inhibition following preincubation with these compounds is not lessened by dialysis for 24 h, implying irreversible binding to the enzyme. In contrast under these conditions the still potent (IC50 27 nM) 17alpha-(4-pyridyl)androst-5-en-3beta-ol (5) showed partial reversal after 5 h of dialysis and complete reversal of inhibition after 24 h. This behavior was also shown by the less potent 16,17-reduced 3-pyridyl compounds 3 and 24. Further, in contrast to the compounds (1, 19, 25, 26) with the 16,17-double bond, the inhibition of the enzymic reaction was not enhanced by preincubation either with 5 or with the 17beta-pyridyl analogues 3, 4, and 24 which also lack this structural feature. The results show that the 16,17-double bond is necessary for irreversible binding of these pyridyl steroids to cytochrome P45017alpha. However oxidation to an epoxide is probably not involved since epoxide 6 was only a moderately potent inhibitor (IC50 260 nM).

Tamoxifen induces selective membrane association of protein kinase C epsilon in MCF-7 human breast cancer cells

Tamoxifen, a synthetic antiestrogen, is known for its antitumoral action in vivo; however, it is well accepted that many tamoxifen effects are elicited via estrogen receptor-independent routes. Previously, we reported that tamoxifen induces PKC translocation in fibroblasts. In the present study, we investigated the influence of tamoxifen, and several triphenylethylene derivatives, on protein kinase C (PKC) in MCF-7 human breast cancer cells. As measured by Western blot analysis, tamoxifen elicited isozyme-specific membrane association of PKC-epsilon, which was time-dependent (as early as 5 min post-treatment) and dose-dependent (5.0-20 microM). Tamoxifen did not influence translocation of alpha, beta, gamma, delta or zeta PKC isoforms. Structure-activity relationship studies demonstrated chemical requirements for PKC-epsilon translocation, with tamoxifen, 3-OH-tamoxifen and clomiphene being active. Compounds without the basic amino side chain, such as triphenylethylene, or minus a phenyl group, such as N,N-dimethyl-2-[(4-phenylmethyl)phenoxy]ethanamine, were not active. In vitro cell growth assays showed a correlation between agent-induced PKC-epsilon translocation and inhibition of cell growth. Exposure of cells to clomiphene resulted in apoptosis. Since PKC-epsilon has been associated with cell differentiation and cellular growth-related processes, the antiproliferative influence of tamoxifen on MCF-7 cells may be related to the interaction with PKC-epsilon.

Phase I and pharmacokinetic study of D-limonene in patients with advanced cancer. Cancer Research Campaign Phase I/II Clinical Trials Committee

PURPOSE

D-Limonene is a natural monoterpene with pronounced chemotherapeutic activity and minimal toxicity in preclinical studies. A phase I clinical trial to assess toxicity, the maximum tolerated dose (MTD) and pharmacokinetics in patients with advanced cancer was followed by a limited phase II evaluation in breast cancer.

METHODS

A group of 32 patients with refractory solid tumors completed 99 courses of D-limonene 0.5 to 12 g/m2 per day administered orally in 21-day cycles. Pharmacokinetics were analyzed by liquid chromatography-mass spectrometry. Ten additional breast cancer patients received 15 cycles of D-limonene at 8 g/m2 per day. Intratumoral monoterpene levels were measured in two patients.

RESULTS

The MTD was 8 g/m2 per day; nausea, vomiting and diarrhea were dose limiting. One partial response in a breast cancer patient on 8 g/m2 per day was maintained for 11 months; three patients with colorectal carcinoma had prolonged stable disease. There were no responses in the phase II study. Peak plasma concentration (Cmax) for D-limonene ranged from 10.8+/-6.7 to 20.5+/-11.2 microM. Predominant circulating metabolites were perillic acid (Cmax 20.7+/-13.2 to 71+/-29.3 microM), dihydroperillic acid (Cmax 16.6+/-7.9 to 28.1+/-3.1 microM), limonene-1,2-diol (Cmax 10.1+/-8 to 20.7+/-8.6 microM), uroterpenol (Cmax 14.3+/-1.5 to 45.1+/-1.8 microM), and an isomer of perillic acid. Both isomers of perillic acid, and cis and trans isomers of dihydroperillic acid were in urine hydrolysates. Intratumoral levels of D-limonene and uroterpenol exceeded the corresponding plasma levels. Other metabolites were trace constituents in tissue.

CONCLUSIONS

D-Limonene is well tolerated in cancer patients at doses which may have clinical activity. The favorable toxicity profile supports further clinical evaluation.

Inhibitory effect of simvastatin on the proliferation of human myeloid leukaemia cells in severe combined immunodeficient (SCID) mice

SCID mice were inoculated intravenously with cells from the human HL60 myeloblastic leukaemia cell line and then treated with the 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase inhibitor, simvastatin, by subcutaneous continuous infusion. The effect of the drug was measured by subsequent colony formation of surviving HL60 cells in vitro and flow cytometry. The number of clonogenic HL60 cells was reduced in the bone marrow of mice that received simvastatin compared with control mice by 65% and 68% in two separate experiments. The number of clonogenic, normal, murine, bone marrow progenitor cells concomitantly exposed to simvastatin in vivo, was not affected in either experiment. Flow cytometric analysis of bone marrow and spleen cells confirmed these results by showing that simvastatin had reduced the percentage of human leukaemia cells in these tissues by 70% and 88% respectively. The data show that the reported selective effect of simvastatin against acute myeloid leukaemia cells in vitro, can be extended to this in vivo model. HL60 bears an N-ras mutation. In further in vitro studies, ketoconazole, an inhibitor of cholesterol biosynthesis post farnesyl pyrophosphate synthesis, had a similar effect to simvastatin on HL60 colony development. Furthermore, the clonogenicity of a population of N-ras mutated, primary acute myeloid leukaemia (AML) cells was no more sensitive to simvastatin than a population without the mutation. The data suggest that the inhibition of AML cell proliferation by simvastatin may be independent of the RAS signalling pathway.

Synthesis and DNA reactivity of alpha-hydroxylated metabolites of nonsteroidal antiestrogens

Tamoxifen [(E)-1-(4-(2-(N,N-dimethylamino)ethoxy)phenyl)-1, 2-diphenylbut-1-ene], a nonsteroidal antiestrogen, induces liver tumors in rats by a genotoxic mechanism. The mechanism of DNA adduct formation is believed to proceed via the formation of a reactive carbocation at the alpha-position from the alpha-hydroxylated metabolite. Molecular mechanics calculations [Kuramochi, H. (1996) J. Med. Chem. 39, 2877-2886] have predicted that 4-substitution will affect the stability of the carbocation and thus will alter its reactivity toward DNA. We have synthesized the putative alpha-hydroxylated metabolites of 4-hydroxytamoxifen [(E)-1-(4-(2-(N, N-dimethylamino)ethoxy)phenyl)-1-(4-hydroxyphenyl)-3-hydroxy-2-phenyl but-1-ene] and idoxifene [(Z)-1-(4-iodophenyl)-3-hydroxy-2-phenyl-1-(4-(2-(N-pyrrolidino) ethoxy)phenyl)but-1-ene] and compared their reactivities with DNA with that of alpha-hydroxytamoxifen [(E)-1-(4-(2-(N, N-dimethylamino)ethoxy)phenyl)-3-hydroxy-1,2-diphenylbut-1-ene]. As predicted, the bis-hydroxylated compound reacted with DNA in aqueous solution at pH 5 to give 12-fold greater levels of adducts than alpha-hydroxytamoxifen, whereas alpha-hydroxyidoxifene gave one-half the number of adducts. The results demonstrate that idoxifene presents a significantly lower genotoxic hazard than tamoxifen for the treatment and prophylaxis of breast cancer.

Length increase of the side chain of idoxifene does not improve its antagonistic potency in breast-cancer cell lines

Linkage of specific residues onto steroidal estrogens through a long aliphatic side chain leads to "pure antiestrogens" devoid of residual estrogenic activity. Therefore, we assessed whether an increase in the length of the side chain of the triphenylethylenic antiestrogen idoxifene might increase its antagonistic potency. Culture of MCF-7 and tamoxifen-resistant variant RTX6 cells in the presence of CB 7675, a (CH2)8 derivative of idoxifene [(CH2)2], ruled out this possibility. This compound partly blocked MCF-7 cell growth only at 10(-6) M to almost the same extent as tamoxifen and failed to inhibit the growth of RTX6 cells, whereas the pure antiestrogen RU 58 668 was effective on both cell lines at much lower concentration. This absence of improvement was reflected in the observation of an efficiency for down-regulating progesterone receptor no better than that of tamoxifen. Pure antiestrogens are known to down-regulate the estrogen receptor, whereas triphenylethylenic antiestrogens up-regulate the receptor; CB 7675 behaves as the latter in agreement with its lack of strong antagonistic activity.

Biochemistry and pharmacokinetics of potent non-steroidal cytochrome P450(17alpha) inhibitors

Two potent non-steroidal inhibitors (CB7645 and CB7661) of human cytochrome P450(17alpha) were tested for in vivo activity in WHT mice. There were no signs of toxicity, but there was no effect on the androgen-dependent organs. The pharmacokinetics and biochemistry of the compounds in mice were investigated. Following i.p. administration of 0.5 mmol/kg of CB7645 and CB7661, peak plasma levels of 13.4 and 3.4 microM, respectively, occurred after 2-4 h, both compounds were cleared rapidly (terminal half-lives 2.7 and 3.3 h, respectively) and neither was detectable at 24 h. CB7645 produced some decrease in plasma testosterone at 4 h, but this was not sustained. When tested in vitro against the WHT testicular enzyme, the CB7645 and CB7661 were competitive inhibitors with K(i) values of 10 and 13 nM, respectively. However, the K(m) for the substrate progesterone was lower at 4.3 nM. These data indicate that, for effective and continuous inhibition of the murine cytochrome P450(17alpha) enzyme, higher peak levels of the compounds would be required, and these levels would need to be maintained throughout the treatment period.

Antagonism of estrogen receptor and calmodulin association by antiestrogens is not dependent on an interaction with calmodulin

Previously, two antiestrogens estradiol derivatives (3 and 4) bearing the basic side chain of tamoxifen were shown to impede the binding of the estrogen receptor (ER) to calmodulin (CaM)-Sepharose. In this study, the interaction of these and related compounds with calmodulin was examined using the cyclic AMP phosphodiesterase (cAMP-PDE) assay. Neither of the steroids gave any significant inhibition of the calmodulin dependent cAMP-PDE activity up to a final concentration of 20 microM. For comparison, tamoxifen and nafoxidine produced IC50 values of 6.7 microM +/- 1.0 and 7.4 microM +/- 1.1, respectively. In addition, a comparison was made of the activity of some triphenylethylene derivatives against CaM dependent cAMP-PDE and the ER-CaM Sepharose assays, but no relationship was observed. Overall, these results demonstrate that inhibition of the ER-CaM association by various steroidal and triphenylethylene antiestrogens does not relate to antagonism of calmodulin function or their binding affinity for the estrogen receptor.

The novel anti-oestrogen idoxifene inhibits the growth of human MCF-7 breast cancer xenografts and reduces the frequency of acquired anti-oestrogen resistance

The effect of idoxifene, a novel anti-oestrogen with less agonist activity than tamoxifen, was compared with that of tamoxifen on the growth of hormone-dependent MCF-7 breast cancer xenografts. Forty tumours were established with oestradiol support in ovariectomized athymic mice, allowed to grow to a median volume of 420 mm3 and then continued with oestradiol, no support, tamoxifen or idoxifene delivered by 1.5-cm silastic capsule. Tumour regression occurred with both anti-oestrogens, although maximum regression was observed following oestradiol withdrawal alone. While prolonged anti-oestrogen therapy was associated with static growth, tumour volumes were significantly lower with idoxifene (P=0.01). After 6 months, 0/10 idoxifene-treated tumours developed acquired resistance compared with 3/10 tumours treated with tamoxifen. In separate experiments, 94 animals were treated initially with oestradiol, tamoxifen, idoxifene or placebo following implantation with 1-mm3 pieces of either wild-type (WT) or tamoxifen-resistant (TR) MCF-7 tumour. After 4 months, only 1/11 WT tumours became established with idoxifene compared with 4/11 with tamoxifen, 8/12 with oestradiol and 0/12 with placebo. Likewise, fewer TR tumours were supported by idoxifene (3/12) than by tamoxifen (8/12) or oestrogen (11/12). These data indicate that, compared with tamoxifen, idoxifene shows reduced growth support of MCF-7 xenografts and may share only partial cross-resistance. Furthermore, the development of acquired anti-oestrogen resistance may be reduced during long-term idoxifene therapy. The drug's reduced agonist activity may, in part, explain these observations and indicate a preferable biochemical profile for breast cancer treatment.

Idoxifene is equipotent to tamoxifen in inhibiting mammary carcinogenesis but forms lower levels of hepatic DNA adducts

Tamoxifen is an effective agent preventing mammary carcinogenesis in rats but causing liver tumours. Idoxifene is a more potent antioestrogen and is effective in patients with advanced breast cancer. We therefore compared the effects of idoxifene with tamoxifen on mammary carcinogenesis and hepatic DNA adduct formation. To do this, we undertook a study designed to compare tamoxifen with idoxifene as a chemopreventive agent in rats inoculated with N-methylnitrosourea (MNU) and also measured hepatic adduct formation. We examined the time to mammary tumour development in 272 female Ludwig/Wistar/Olac rats treated with MNU followed by tamoxifen (5 mg kg(-1)), equimolar idoxifene or vehicle three times a week for up to 24 weeks. To determine duration of effect, a second study was carried out whereby all of the 129 animals surviving at the end of treatment were entered into a surveillance programme for 27 weeks after the end of the administration period. Hepatic DNA adduct formation was examined by 32P-postlabelling in a group of rats after 24 weeks' treatment. In the first study, both idoxifene and tamoxifen were effective in preventing tumour growth as only 2 out of 21 (10%) MNU and vehicle-treated animals were alive and tumour free after 24 weeks compared with 13 out of 22 (59%) animals receiving MNU followed by idoxifene or tamoxifen (P < 0.001). The second study showed that, in both idoxifene- and tamoxifen-treated animals, a progressive regrowth of tumours occurred after cessation of therapy, as by the end of the observation period only four idoxifene-treated animals and one tamoxifen-treated animal were free from disease. In the subset of animals tested, tamoxifen-treated animals had approximately 100 times higher levels of DNA hepatic adducts than idoxifene-treated animals. Adducts were not seen in the control group. These results indicate that idoxifene is as effective a chemopreventive agent as tamoxifen in the rat while causing only very low levels of DNA adducts in liver tissue and suggest that idoxifene may be a well-tolerated chemopreventive agent in women who are at increased risk of breast cancer.

Pre-clinical development of the anti-tumour agent CB 7646, bis N-(hydroxymethyl) trimethylmelamine, a stable analogue of trimelamol

Formulation difficulties prevented the otherwise promising clinical development of the anti-tumour agent trimelamol (TM; tris-[hydroxymethyl]trimethylmelamine]). A synthetic analogue programme resulted in the identification of CB 7646 (bis N-[hydroxymethyl]trimethylmelamine) as a compound with improved stability and favourable formulation characteristics. The in vitro and in vivo activity of CB 7646 was shown to be very similar to that of TM. In addition, curative activities were shown in the PXN/65 human ovarian cancer xenograft and the MX-1 and T-61 human breast cancer xenograft models. The effectiveness of the N-(hydroxymethyl)melamines against platinum-refractory disease was noted in the phase I clinical trial of TM. In line with this finding, the present study confirmed the effective activity of both TM and CB 7646 against various forms of platinum resistance in in vitro models. Curative activity for TM and CB 7646 was seen in the HX110P human ovarian cancer xenograft with acquired carboplatin resistance. Animal studies indicated less neurotoxicity for CB 7646 than for TM. The pharmacokinetic profile of CB 7646 indicated a decreased plasma elimination, indicative of slower in vivo degradation than for TM. CB 7646, therefore, represents a promising candidate for clinical development, designed to supersede TM.

3- and 4-pyridylalkyl adamantanecarboxylates: inhibitors of human cytochrome P450(17 alpha) (17 alpha-hydroxylase/C17,20-lyase). Potential nonsteroidal agents for the treatment of prostatic cancer

Various 3- and 4-pyridylalkyl 1-adamantanecarboxylates have been synthesized and tested for inhibitory activity toward the 17 alpha-hydroxylase and C17,20-lyase activities of human testicular cytochrome P450(17 alpha). The 4-pyridylalkyl esters were much more inhibitory than their 3-pyridylalkyl counterparts. The most potent was (S)-1-(4-pyridyl)ethyl 1-adamantanecarboxylate (3b; IC50 for lyase, 1.8 nM), whereas the (R)-enantiomer 3a was much less inhibitory (IC50 74 nM). Nearly as potent as 3b was the dimethylated counterpart, the 2-(4-pyridylpropan-2-yl) ester 5 (IC50 2.7 nM), which was also more resistant to degradation by esterases. In contrast to their 4-pyridyl analogs, the enantiomers of the 1-(3-pyridyl)ethyl ester were similarly inhibitory (IC50 for lyase; (R)-isomer 8a 150 nM, (S)-isomer 8b 230 nM). Amides corresponding to the 4-pyridylmethyl ester 1 and the (S)-1-(4-pyridyl)ethyl ester 3b, respectively 11 and 15b, were much less inhibitory than their ester counterparts. On the basis of a combination of inhibitory potency and resistance to esterases, the ester 5 was the best candidate for further development as a potential nonsteroidal inhibitor of cytochrome P450(17 alpha) for the treatment of prostate cancer.

The activity of N-(hydroxymethyl) melamines in fresh human ovarian tumour cells and xenografts

Trimelamol (TM) was developed as a water soluble analogue of the oral chemotherapeutic agent hexamethyl-melamine (HMM), to be administered i.v., in an effort to avoid dose limiting emesis. Because of formulation difficulties due to its inherent instability the development of TM was halted. In vivo studies using a human ovarian cancer xenograft model PXN/65 showed TM to be curative in the dose range of 15-60 mg/kg i.p. daily x 5, for 4 weeks. Conversely, HMM given at the highest dose (60 mg/kg i.p., or 90 mg/kg p.o.) indicated only very modest tumour growth delays. In vitro chemosensitivity testing using primary ovarian tumour cultures showed that in 12/23 cases indicating reduced sensitivity to cisplatin or carboplatin, sensitivity to TM was increased. TM was curative in the carboplatin-resistant HX 110P human ovarian cancer xenograft and promising activity was seen in the MX-1 human breast cancer xenograft. In spite of enhanced stability in aqueous solution and good in vitro cytotoxicity, the TM analogues CB 7669 (triscyanomethyl) and CB 7639 (tristrifluoroethyl) showed disappointing in vivo antitumour activity which may be explained by the need for prolonged exposure. TM analogues with intermediate stability are currently under development in an effort to further the clinical development of this promising group of antitumour agents.

Identification and characterization of limonene metabolites in patients with advanced cancer by liquid chromatography/mass spectrometry

Limonene is a farnesyl transferase inhibitor that has shown antitumor properties. The drug had been given orally to cancer patients. Plasma and urine samples collected from the patients were examined by reversed-phase HPLC-atmospheric pressure chemical ionization and electrospray ionization MS. The drug underwent rapid conversion to hydroxylated and carboxylated derivatives. Characterization and structural elucidation of the metabolites were achieved by LC/MS and NMR. Five major metabolites were detected in the plasma extracts, namely limonene-1,2-diol, limonene-8,9-diol, perillic acid, an isomer of perillic acid, and dihydroperillic acid. Urinary metabolites comprised the glucuronides of the two isomers of perillic acid, dihydroperillic acid, limonene-8,9-diol, and a monohydroxylated limonene.