Longitudinal associations between mental health and social environment in older adults: a multilevel growth modeling

OBJECTIVES

This study aimed to assess longitudinal relationships between social environment indicators (social connectedness, social engagement, social contribution) and mental health indicators (depression and anxiety) among community-dwelling adults age 55 years and older.

METHODS

Data were drawn from 3-waves of the national longitudinal survey of Midlife Development in the United States (MIDUS) (N = 2,020; age range = 55-94 years). We developed multilevel growth models to ascertain the relationships of interest, controlling for sociodemographic and physical health factors.

RESULTS

Over the 20-year period of study, lower levels of emotional social support, social integration and social contribution significantly predicted depression and anxiety, whereas social network and social engagement were not significant predictors of these mental health outcomes in older adults. The models also indicated a moderation effect of the number of chronic conditions on the slopes of depression and anxiety.

DISCUSSION

Considering our findings, interventions to enhance social contribution and social connectedness could be effective to help older adults maintain positive mental health, as well as programs that facilitate older adults' connections with their families, communities and health care providers. These interventions must also account for multiple chronic conditions since functional limitations drive declining integration in the community and participation in social activities.

Increasing the Repertoire for Depression Care: Methods and Challenges of a Randomized Controlled Trial of Peer Support for Vulnerable Older Adults

OBJECTIVE

Low-income White and older adults of color face barriers to depression care. Our purpose is to describe the methods and challenges encountered during the implementation of a randomized controlled trial to test the effectiveness of a peer support depression care intervention for low-income White and older adults of color during the COVID-19 pandemic.

METHODS

Peer Enhanced Depression Care (Peers) is an 8-week community-based intervention that uses peer mentors who are trained and supervised to provide social support and self-care skills to depressed older adults. The effectiveness of the intervention in reducing depression will be evaluated by following a sample of older adults recruited in the community over a 12-month period. Target enrollment is 160 older adults. We hypothesize that participants randomized to the Peer Enhanced Depression Care intervention will experience greater decrease in depressive symptoms compared to participants randomized to the social interaction control. We provide lessons learned regarding the recruitment of BIPOC and White low-income older adults and peer mentors during the COVID-19 pandemic.

RESULTS

Recruitment challenges occurred in primary care clinics that were unable to accommodate recruitment efforts during the pandemic. This led to focused outreach to community-based organizations serving older adults. Challenges to participant recruitment have included barriers related to stigma, distrust, as well as unfamiliarity with research. Peer mentor recruitment was facilitated by existing government-supported resources.

CONCLUSIONS

This study will provide knowledge regarding the effectiveness, mechanism, and processes of delivering an informal psychosocial intervention such as peer support to a vulnerable older adult population.

Socially Assistive Humanoid Robots: Effects on Depression and Health-Related Quality of Life among Low-Income, Socially Isolated Older Adults in South Korea

Using a mixed-method study design, we examined the effects of a socially assistive humanoid robot (SAHR), called Hyodol, on depressive symptoms and health-related quality of life (HRQOL) of low-income, socially isolated older adults (N = 180). Quantitative outcomes were assessed at baseline (before Hyodol deployment) and at 3 and 6 months after baseline. Results showed reduced depressive symptoms and improved HRQOL at 3 months; however, these positive effects did not extend to 6 months. Ten focus group participants perceived Hyodol to be a valuable companion especially during the COVID outbreak. These results suggest that while Hyodol may have provided companionship for some low-income, socially isolated older adults during home confinement, its effects on depression and HRQOL were limited. Further research is needed to assess long-term effects of SAHRs as appropriate tools for reducing social isolation and improving behavioral health among community-dwelling older adults.

PUBLIC MENTAL HEALTH SERVICE USE AMONG US ADULTS AGE 50+ COMPARED TO YOUNGER AGE GROUPS

Despite increasing numbers of older-adult mental health service users, few studies have examined their use of public mental health services. Using the 2018 and 2019 Mental Health-Client Level data (N=4,291,737 in 2018 and N=4,513,946 in 2019 for those age 18+), we examined age group differences in the types of mental disorders diagnosed in outpatient-only, both outpatient and inpatient, and inpatient-only service settings. Of all users, 25.3% were age 50-64 and 6.7% were age 65+. Multivariable logistic regression results, controlling for gender, race/ethnicity, census region, and alcohol/substance use disorder, showed that compared to the 30-49 age group, the 50-64 and 65+ age groups had higher odds of having depressive disorder in outpatient-only settings (aOR=1.28 [95% CI=1.28-1.29] and aOR=1.08 [95% CI=1.08-1.09] for the 50-64 and 65+ age groups, respectively). Both older groups also had higher odds of delirium/dementia disorder in all three service settings. In addition, they had consistently higher odds of a diagnosis of schizophrenia or other psychotic disorder in all three service settings (aOR=1.88 [95% CI=1.86-1.89], aOR=1.70 [95% CI=1.65-1.74], and aOR=1.44 [95% CI=1.39-1.49] in outpatient, both outpatient and inpatient, and inpatient-only settings, respectively). Community mental health centers (CMHC) are on the frontlines in serving vulnerable communities and received increased federal funding during the COVID-19 pandemic. Our findings indicate that CMHCs also need programs dedicated to and tailored for older adults. More research is also needed on older adults who receive public mental health services and unmet mental health needs among low-income older adults with serious mental illness.

ADDRESSING THE MENTAL HEALTH NEEDS OF HOMEBOUND OLDER ADULTS IN AGING SERVICE SETTINGS

Despite significant and urgent mental health needs among low-income homebound older adults, the existing mental health service systems’ reach for these older adults is almost nonexistent. Given the current and projected geriatric mental health workforce shortages, innovative approaches are needed to better serve these underserved older adults. This presentation will focus on a series of randomized clinical trials that tested acceptable and feasible mental health service delivery models for homebound older adults who are served by aging service network agencies that provide hot meals and case management. Findings from the real-world effectiveness trials of tele-delivered behavioral activation treatment for depression and loneliness by bachelor’s-level lay counselors who are embedded in aging service agencies will be shared. Ways to promote a wider adoption of scalable and sustainable mental health service delivery models for homebound older adults will be discussed.

Unanticipated Changes in Drug Overdose Death Rates in Canada During the Opioid Crisis

Escalating drug overdose death rates in Canada are of ever-increasing concern. To better understand the extent of this health threat, we obtained mortality statistics and population figures for the years 2000 to 2020, and examined rates of overdose deaths, coded (using ICD-10) as accidental, suicide or "undetermined intent." The drug deemed as primarily responsible for the death was categorized as opioid, non-opioid, or unspecified. Age patterns of drug deaths were graphed. Joinpoint analysis was used to test the significance of changes in death rates. Accidental opioid and stimulant overdose death rates in Canada have climbed faster since 2011, though not as high as corresponding US rates. Unknown cause death rates have increased. However, opioid and non-opioid suicide rates have decreased significantly since 2011, and there have been fewer drug deaths of undetermined intent. Increased attention to the possibility that some suicides are being misclassified is warranted.

Older Nonmedical and Medical Cannabis Users: Health Characteristics, Cannabis Use Patterns, and Cannabis Sources

Despite rapidly growing number of older medical cannabis users, research on them is scant. In this study, we examined medical and nonmedical cannabis users aged 50+ on health-related characteristics and cannabis use patterns and sources. Hypotheses were that compared to nonmedical users, medical users are more likely to have physical and mental health problems, use healthcare services, discuss their drug use with a healthcare professional, use cannabis more frequently, and purchase cannabis from a medical dispensary and other sources rather than obtain it as a gift, share someone else’s, or use other means. We used the 2018 and 2019 National Survey on Drug Use and Health data (N=17,685 aged 50+; male=8,030; female=9,655) and multivariable logistic regression analysis to test hypotheses. Of the sample, 8.9% reported past-year cannabis use. Of past-year users, 18.5% reported any medical use. Of medical users, 70.9% reported exclusive medical use and 29.1% reported using medically and nonmedically. A large proportion obtained cannabis from private/informal sources. Any medical use, compared to nonmedical use, was associated with lower odds of alcohol use disorder but higher odds of discussing drug use with a healthcare professional (AOR=4.18, 95% CI=2.53-6.89), more days of use (AOR=2.56, 95% CI=1.35-4.86 for 200-365 days), and purchase at a medical cannabis dispensary (AOR=4.38, 95% CI=2.47-7.76). Medical and nonmedical users did not differ on physical health, and both had high behavioral health problem rates. However, only a small portion discussed their drug use with a healthcare professional. More healthcare professional attention to older cannabis users is needed.

Optimal application of compressive palatal stents following mesiodens removal in pediatric patients: A Randomized Controlled Trial

Background

There is no scientific evidence supporting the choice of a palatal stent in patients who underwent removal of an impacted supernumerary tooth. We aimed to investigate the effects of palatal stents in patients who underwent supernumerary tooth removal through a palatal approach and to suggest the optimal stent thickness and material.

Material and Methods

We recruited 144 patients who underwent extraction of a supernumerary tooth between the maxillary anterior teeth. Subjects were assigned to a control group (CG) or one of four compressive palatal stent groups (CPSGs) classified by the thickness and material of the thermoplastic acrylic stent used. Palatal gingival swelling and objective indices (healing, oral hygiene, gingival, and plaque) were evaluated before surgery and on postoperative days (PODs) 3, 7, and 14; pain/discomfort and the Child Oral Health Impact Profile (COHIP) were assessed as subjective indices of the effects of the stent.

Results

The CPSGs showed faster healing than did the CG on PODs 7 (P<0.001) and 14 (P=0.043); swelling was measured by 1.64±0.88 mm and 4.52±0.39 mm, respectively. Although swelling was least in the 4-mm hard group (0.92±0.33 mm), the difference compared with that in the 2-mm hard group (1.01±0.18 mm) was not significant (P=0.077). The CPSGs showed better COHIP (P<0.001-0.036) and pain scores (P<0.001) than did the CG on PODs 1-3.

Conclusions

Compressive palatal stents reduce discomfort by decreasing pain and alleviating swelling. Although a stent is effective regardless of its thickness and material, 2-mm hard stents maximized such positive effects with minimal discomfort.

Key words:Supernumerary tooth, tooth Extraction, postoperative care, oral Health, pediatric dentistry.

Prescription Pain Reliever Use and Misuse Among Marijuana Users Age 50+ Years

Marijuana use among individuals aged 50+ has steadily increased over the past decade, with 8% reporting past-year use in 2018. National epidemiologic data also showed a 36% rate of past-year prescription pain reliever (PPNR) use in the 50+ age group in 2018, a decrease from 40% in 2015, but still significantly higher than for younger age groups. Little research has, however, focused on older adults’ dual recreational and/or medical marijuana and PPNR use. This study, based on the 2015-2018 National Survey of Drug Use and Health, examined rates and correlates of dual marijuana and PPNR use and misuse among those aged 50+ who reported past-year marijuana use (N=2,632). Our findings showed that 43.6% of past-year marijuana users did not use any PPNR, 47.1% used PPNR but did not misuse, and 9.4% misused PPNR in the past year, showing that one in six dual marijuana and PPNR users reported misusing PPNR. The risks of PPNR use/no misuse and PPNR misuse were higher among those who had more chronic medical conditions and major depressive episode. Additionally, the risk of PPNR use/no misuse was associated with high frequency and medical marijuana use; and the risk of PPNR misuse was associated with younger marijuana initiation age and marijuana and other illicit drug use disorders. Thus, correlates of dual marijuana and PPNR use/misuse among older adults are poor physical and mental health problems and problematic marijuana use. Older adults with marijuana and PPNR misuse need access to evidence-based treatments for pain management and substance misuse.

Hypoxia improves hair inductivity of dermal papilla cells via nuclear NADPH oxidase 4-mediated reactive oxygen species generation'

BACKGROUND

Dermal papilla cells (DPCs) play a key role in hair regeneration and morphogenesis. Therefore, tremendous efforts have been made to promote DPC hair inductivity.

OBJECTIVES

The aim of this study was to investigate the mitogenic and hair inductive effects of hypoxia on DPCs and examine the underlying mechanism of hypoxia-induced stimulation of DPCs.

METHODS

DPCs' hair inductivity was examined under normoxia (20% O₂ ) and hypoxia (2% O₂ ).

RESULTS

Hypoxia significantly increased the proliferation and delayed senescence of DPCs via Akt phosphorylation and downstream pathways. Hypoxia upregulated growth factor secretion of DPCs through the mitogen-activated protein kinase pathway. Hypoxia-preconditioned DPCs induced the telogen-to-anagen transition in C₃ H mice, and also enhanced hair neogenesis in a hair reconstitution assay. Injected green fluorescent protein-labelled DPCs migrated to the outer root sheath of the hair follicle, and hypoxia-preconditioning increased survival and migration of DPCs in vivo. Conditioned medium obtained from hypoxia increased the hair length of mouse vibrissa follicles via upregulation of alkaline phosphatase, vascular endothelial growth factor, and glial cell line-derived neurotrophic factor. We examined the mechanism of this hypoxia-induced stimulation, and found that reactive oxygen species (ROS) play a key role. For example, inhibition of ROS generation by N-acetylcysteine or diphenyleneiodonium treatment attenuated DPCs' hypoxia-induced stimulation, but treatment with ROS donors induced mitogenic effects and anagen transition. NADPH oxidase 4 is highly expressed in the DPC nuclear region, and NOX4 knockout by CRISPR-Cas9 attenuated the hypoxia-induced stimulation of DPCs.

CONCLUSIONS

Our results suggest that DPC culture under hypoxia has great advantages over normoxia, and is a novel solution for producing DPCs for cell therapy. What's already known about this topic? Dermal papilla cells (DPCs) play a key role in hair regeneration and morphogenesis, but they are difficult to isolate and expand for use in cell therapy. Tremendous efforts have been made to increase proliferation of DPCs and promote their hair formation ability. What does this study add? Hypoxia (2% O₂ ) culture of DPCs increases proliferation, delays senescence and enhances hair inductivity of DPCs. Reactive oxygen species play a key role in hypoxia-induced stimulation of DPC. What is the translational message? Preconditioning DPCs under hypoxia improves their hair regenerative potential, and is a novel solution for producing DPCs for cell therapy to treat hair loss.

Creating virtual 3-dimensional models for teaching pre-clinical tooth preparation: Students' usages and perceptions

PURPOSE

This research aimed to evaluate the students' usage and perceptions of using smartphones in their general dental education and learning tooth preparation with the individually designed virtual 3D instructional models in the pre-clinical removable partial denture course.

MATERIALS AND METHODS

Second-year dental students were asked to voluntarily participate in a survey to investigate their demographic information, general usages of smartphones, perception of smartphones usage in dental education (construct 1) and perception of individually designed virtual 3D instructional models (construct 2). Students' responses of general usages of the smartphones were compared with their demographic and educational backgrounds using nonparametric Kruskal-Wallis test (for age) and Fisher's exact test (for sex, race and educational background). The sums of scores of the construct 1 and construct 2 were tested for associations with student's demographic and educational backgrounds using the Pearson product-moment correlation (for age), t test (for sex and educational background) or one-way ANOVA F test (for race) (α = .05).

RESULTS

A 75% response rate (N = 90) was achieved in this study, and all 90 participants owned smartphones. Students' responses to general usages of the smartphones were not significantly influenced by their demographic background. For the construct 1, more than 73% of participants responded either agree or strongly agree to the usage of smartphones in general dental education and pre-clinical setting; however, only 49% of participants responded the same way in the clinical setting. For the construct 2, 48 of 90 participants viewed the 3D models, and more than 73% of these 48 participants responded either agree or strongly agree to the usage of the 3D models in the pre-clinical course. Student's demographic background did not have significant influence on the sums of scores of the construct 1 and construct 2.

CONCLUSIONS

Within the limitations of this study, high usages and ownerships of smartphones were found amongst the students surveyed. The individually designed virtual 3D instructional models as supplemental teaching materials in the pre-clinical course were perceived positively by the students.

Reciprocal Effects Between Health and Social Support in Older Adults’ Relationships With Their Children and Friends

This study examined the longitudinal reciprocal effects between health and social support in older adults’ relationships with their children and friends. Data are from the 2006 and 2010 waves of the Health and Retirement Study ( N = 3,760). We focused on three specific aspects of social support: frequency of contact, positive interactions, and negative interactions. We used autoregressive cross-lagged models to examine the bidirectional effects between social support and health. When the bidirectional effects between health and social support were simultaneously examined, the longitudinal effect of social support on health was not significant. In contrast, older adults’ poor health was associated with decreased contact and decreased positive interactions with friends as well as with increased negative interactions with their adult children and friends. The findings suggest that older adults’ poor health has a negative impact on their social relationships and that such effect surpasses the impact of social relationships on health.

Meta-analysis of problem solving therapy for the treatment of major depressive disorder in older adults

OBJECTIVE

Major depressive disorder (MDD) affects many older adults and is associated with poor medical and mental health outcomes. Problem Solving Therapy (PST) has emerged as a promising psychotherapy for MDD in older adults, although the efficacy of PST in this population has not been well described. We examined the effectiveness of PST for the treatment of MDD in older adults in a systematic review and meta-analysis.

METHODS

We searched electronic databases to identify randomized controlled trials comparing PST to a control condition or other treatment for MDD in adults with an average age of 60 years or older. We used meta-analysis to arrive at pooled summary measures of the efficacy of PST when compared to control conditions on the change in depressive symptoms and other outcomes.

RESULTS

Nine studies with a total of 569 participants (290 PST, 279 control) met inclusion criteria. Most studies administered PST in person and were between 6 and 12 weeks in duration. Meta-analysis of six studies evaluating the effect of PST on depression using the Hamilton Rating Scale for Depression identified a significant reduction in depression associated with PST (pooled mean difference = -6.94, 95%CI -10.91 to -2.97, d = 1.15, P = 0.0006). PST was also effective in reducing disability in studies reporting this outcome.

CONCLUSIONS

Our review supports the existing research literature on PST suggesting that it is an effective treatment for older people with MDD. Further study is required to understand long-term outcomes associated with PST and its efficacy when compared to other treatments.

Abstract LB-308: Combination of CTx-0294945 a highly selective inhibitor of focal adhesion kinase with bevacizumab in pre-clinical models of breast cancer

Background: Focal adhesion kinase (FAK) is a non-receptor tyrosine kinase that provides a critical hub for signalling from at least four different classes of cellular sensing mechanisms including growth factor receptors, GPCRs, integrins and mechanical stress forces. By temporal and spatial integration of signals from these sources, FAK plays a central role in cell migration, invasion and proliferation; processes vital for tumorigenesis. The significance of FAK to the function of signal transduction pathways provides a strong rationale for the combination of FAK inhibitors with other targeted agents to achieve improved efficacy against a range of cancers. Others have demonstrated the importance of FAK in angiogenesis and therefore combining a FAKi with anti-VEGF agents is attractive as it employs two complementary mechanisms of suppressing the formation of tumor vasculature. Here we present results from the co-administration of CTx-0294945, a highly selective FAKi, and bevacizumab (bev) in an orthotopic model of human breast cancer. Methods and Results: CTx-0294945 is an orally bioavailable small molecule ATP competitive inhibitor of focal adhesion kinase (FAK KD=0.21 nM). It exhibits high selectivity against a diverse panel of 125 kinases including the closely related Pyk2. CTx-0294945 inhibits autophosphorylation of 397Y-FAK in MDA-MB-231 cells with an IC50 = 7 nM and exhibits low general cellular toxicity (IC50 = 2.7 µM, MDA-MB-231 cells). CTx-0294945 is suitable for oral administration (%F=58 and t1/2=5.1 h at 20 mg/Kg in rat) and does not inhibit (IC50 &gt;20 µM) any of the cytochrome p450 isoforms tested to date. To assess the co-administration of CTx-0294945 with bev, mice were injected orthotopically with MDA-MB-231 cells (106). After 14 days, when tumors were palpable, mice were randomized into 4 groups and dosing commenced. The groups were treated with CTx-0294945 (80 mg/kg QD, PO), bev (12.5 mg/Kg IP, x2/week), CTx-0294945 (80 mg/Kg QD, PO) and bev (12.5 mg/Kg IP, x2/week) or vehicle. Tumor growth was monitored and on day 28 animals in the vehicle and CTx-0294945 arms were culled when the size of the tumors reached ethical end point (1000 mm3). Tumor growth in the bev only and the CTx-0294945 + bev arms was significantly inhibited (75% and 88% TGI respectively). At this time the treatment regimes for both cohorts were stopped and tumor growth allowed to progress. After an additional 14 days the experiment was terminated when the bev treatment group reached ethical end point; however the average size of the tumors in the CTx-0294945 + bev cohort was still was only 562 mm3. Conclusions: Our data suggest the potential utility of combining a selective FAK inhibitor with bevacizumab to prevent tumour progression and enhance the durability of response.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr LB-308. doi:1538-7445.AM2012-LB-308

Relationship between health service use and health information technology use among older adults: analysis of the US National Health Interview Survey

BACKGROUND

Older adults are the most frequent and heaviest users of health services in the United States; however, previous research on older adults' use of health information technology (HIT) has not examined the possible association of HIT use among older adults with their use of health services.

OBJECTIVE

This study examined the relationship between US older adults' use of health services and their use of the Internet for health-related activities, controlling for socioeconomic characteristics and aging-related limitations in sensory and cognitive function. It also examined gender differences in the pattern of association between the types of health services used and HIT use.

METHODS

The data for this study were drawn from the 2009 US National Health Interview Survey (NHIS), which was the first nationally representative household survey to collect data on HIT (Internet) use. First, the rates of lifetime and 12-month HIT use among sample adults (n = 27,731) by age group (18-29 to 85 and over) were analyzed. Second, bivariate analysis of sociodemographic characteristics, health status, and health service use by HIT use status among those aged 65 or older (n = 5294) was conducted. Finally, multivariate binary logistic regression analysis was used to test the study hypotheses with 12-month HIT use as the dependent variable and 12-month health service uses among the age group 65 or older as possible correlates.

RESULTS

The rates of HIT use were significantly lower among the age groups 65 or older compared with the younger age groups, although the age group 55 to 64 was not different from those younger. The rates of HIT use decreased from 32.2% in the age group 65 to 74 to 14.5% in the age group 75 to 84 and 4.9% in the 85 and older age group. For both genders, having seen or talked to a general practitioner increased the odds of HIT use. However, having seen or talked to a medical specialist, eye doctor, or physical therapist/occupational therapist (PT/OT) were significantly associated with HIT use only for older women, while having seen or talked to a mental health professional only marginally increased the odds of HIT use only for older men. Having visited or talked to a chiropractor and having had overnight hospitalization, surgery, and/or homecare services were not associated with the odds of HIT use for either gender.

CONCLUSIONS

Older-adult users of general health services were more likely to use HIT than nonusers of general health services, while older-adult users of specialized health services were not different from nonusers of specialized health services in their odds of HIT use. The findings have implications for narrowing the age-related and socioeconomic status-related gaps in HIT use. The access gaps among racial/ethnic minority older adults and poorly educated and/or low-income older adults are especially striking and call for concerted efforts to facilitate Internet access and HIT use among these disadvantaged older adults.

Phase II cisplatin, irinotecan, cetuximab and concurrent radiation therapy followed by surgery for locally advanced esophageal cancer

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Background: Weekly irinotecan, cisplatin, and concurrent radiation therapy is a well-tolerated, active regimen in locally advanced esophageal cancer. (Ilson. JCO 2003) Cetuximab, an EGFR inhibitor, is a potent radiation sensitizer in head and neck cancer. (Bonner. Proc ASCO 2004) Methods: In this phase II trial, patients (pts) with T2–4N0–1M0–1A esophageal adenocarcinoma (A) or squamous cell carcinoma (S) receive 5040 cGy/28 fractions of radiation therapy (RT) and concurrent weekly cisplatin 30mg/m2 plus irinotecan 65 mg/m2 on weeks 1, 2, 4, and 5, followed by surgery 4–8 weeks after completion of RT. Additionally, pts receive weekly infusions of cetuximab 250 mg during RT, up to one week before surgery, and for 6 months following surgery. Results: Seventeen pts have been entered: male: female = 14:3, median age 54, ECOG PS 0:1 = 6:11, A:S = 17:0, stage IIA:IIB:III:IVA = 6:1:8:2, tumor location-esophagus-mid:lower:gastroesophageal junction = 1:4:12, >10% weight loss-yes:no = 8:9. Of 17 pts entered, 15 pts have proceeded to surgery, 1 pt died from Aspergillus infection resulting in respiratory failure and sepsis, and 1 pt is pending surgery. Of the 15 pts who underwent surgery, 2 (13%) had a complete pathologic response; pathologic stage for other pts: 0 = 1, I = 3, IIA = 3, IIB = 1, III = 4, IV = 1. Grade III/IV toxicity (17 pts) was: diarrhea 9 pts, neutropenia 9 pts, febrile neutropenia 5 pts, anorexia 5 pts, vomiting 4 pts, fatigue 3 pts, mucositis 1 pt. Chemotherapy dose attenuation was required for diarrhea in 5 pts, for neutropenia in 4 pts, and for folliculitis in 1 pt. One patient was removed from study during week 6 for prolonged diarrhea/ dehydration. Due to the 2-step design of the trial, accrual is on hold pending a 3rd required pathologic CR in the first 17 patients. Conclusions: Compared to other trials of irinotecan, cisplatin, radiation therapy, and surgery in similar groups of esophageal cancer patients, early results for this combination with cetuximab suggest a lower complete response rate and higher overall toxicity. Additional data will be available at ASCO. Supported by Bristol-Myers Squibb.

No significant financial relationships to disclose.

Studies of site selective hydrogen atom abstractions by Cl atoms from isobutane and propane by laser flash photolysis/IR diode laser spectroscopy

The kinetics of chlorine atom abstractions from normal and selectively deuterated propane and isobutane have been measured at room temperature and 195 K using a laser flash photolysis system, and following the course of the reaction via IR diode laser absorption measurements of HCl product. In conjunction with the kinetic measurements, a comparison of the HCl signal heights from pairs of measurements on normal and selectively deuterated systems has allowed the determination of the branching fractions of the reactions at the primary, secondary (propane) and tertiary (isobutane) positions. The kinetic data (all in units of cm(3) molecule(-1) s(-1)) for the reaction of Cl atoms with propane ((1.22 +/- 0.02) x10(-10), 195 K; (1.22 +/- 0.03) x10(-10) 298 K) and isobutane ((1.52 +/- 0.02) x10(-10), 195 K; (1.25 +/- 0.04) x10(-10), 298 K) are generally in good agreement with literature data. No data are available for comparison with our measurements for the reactions of Cl atoms with CH(3)CD(2)CH(3) ((1.02 +/- 0.03) x10(-10), 195 K; (1.09 +/- 0.02) x10(-10), 298 K) or (CH(3))(3)CD ((1.32 +/- 0.03) x10(-10), 195 K; (1.12 +/- 0.04) x10(-10), 298 K). Rate coefficients at 195 K for the reactions of Cl atoms with ethane ((5.04 +/- 0.08) x10(-11) and n-butane ((2.19 +/- 0.03) x10(-10)) were also measured. The branching fractions for abstraction at the primary position increased with temperature for both propane ((40 +/- 3)% at 195 K to (48 +/- 3)% at 298 K) and isobutane ((49 +/- 4)% at 195 K to (62 +/- 5)% at 298 K). The direct measurements from this study are in good agreement with most calculations based on structure activity relationships.

Usefulness of reversed display of soft-copy abdominal radiographs for urinary calculi detection

PURPOSE

To determine the usefulness of reversed display of soft-copy abdominal radiographs for urinary calculi detection.

MATERIAL AND METHODS

Sixty radiographs with a single urinary calculus less than 5 mm in the long diameter (15 in the kidney; 15 in the proximal ureter; 15 in the mid-ureter, 15 in the distal ureter) and 15 radiographs without calculi were evaluated. Four readers blinded to the presence or absence of urinary calculi on each radiograph reviewed the radiographs in the conventional display, reversed display, and combination of conventional and reversed displays at 1-week intervals. All images were evaluated in random order and the presence or absence of urinary calculi was interpreted using the confidence score from 1 to 5.

RESULTS

Multireader analysis for calculi in all locations showed a greater area under the receiver operating curve for combination of the two displays (0.764) than for the conventional display alone (0.655) (P=0.031). In the single-reader analysis for calculi in all locations, the third reader showed a greater area under the receiver operating curve for the reversed display (0.784) than for the conventional display (0.622) (P=0.027). Multireader analysis of the calculi in the kidney showed a greater area under the receiver operating curve for combination of the two displays (0.824) than for the conventional display alone (0.703) (P=0.043).

CONCLUSION

The reversed display of soft-copy abdominal radiographs may be useful for urinary calculi detection.

RecA-double stranded DNA complexes studied by atomic force microscopy

RecA-double stranded (ds) DNA complexes have been studied by atomic force microscopy (AFM). When the complexes were prepared in the presence of ATP gamma S, fully covered RecA-dsDNA filaments were observed by AFM. When the concentration of RecA proteins was lower, various lengths of filaments were found. The variation of the observed structures may directly reflect the real distribution of the intermediate complexes in the reaction mixture, as the mixture was simply deposited on a mica surface for AFM observation without special fixation or staining. The use of a carbon nanotube (CNT) AFM tip enabled high resolution to reveal the periodicity of RecA-dsDNA filaments. Our observations demonstrated the potential of the AFM method for the structural studies of the RecA-dsDNA complexes, especially their intermediate states.