US RACIAL AND ETHNIC DISPARITIES IN DEMENTIA LIFE EXPECTANCY, RISK/PROTECTIVE FACTORS, AND CAREGIVING STRESSORS

The health, emotional, and economic impacts of dementia are far-reaching and impossible to fully calculate. Late-life dementia is not equitably distributed across population subgroups including older people and racial/ethnic minorities. Clear evidence underscores disparities in social/personal resources, environmental exposures, racism/discrimination, increased burden of caregiving, and uneven access to quality care especially for Blacks and Hispanics and caregivers. Each paper in this symposium addresses high-priority, disparity research areas highlighted in the recent NASEM Decadal Survey of Behavioral and Social Science Research on ADRD: characteristics of population groups that influence disease ascertainment and dementia life expectancy; quantification of mid- and late-life risk/protective factors; pesticide exposure and cognition, and caregiving stressors among racial/ethnic minorities. All presentations utilize nationally representative data on older people in the US. Garcia et al. utilize HRS data to create dementia life expectancy estimates using four competing algorithmic classifications of dementia status by race/ethnicity (Blacks, Whites), nativity status (US-, non-US-born Latinos), and gender. Applying the Lancet Commission Dementia Prevention framework to HRS data, Ferdows and Aranda examine risk/protective factors and quantify the relative contribution of individual variables in explaining racial/ethnic dementia disparities. Chanti-Ketterl et al. elucidate the association between organochlorines pesticides (total scores, specific type) and cognition based on NHANES data to ascertain racial/ethnic differences. Based on NHATS, Moon et al. explore differences in primary stressors by dementia care and race (Blacks, Whites) during COVID-19. Findings provide evidence of potential multi-level targets for interventions and public policies. All primary authors are early-career scholars dedicated to mitigating ADRD health disparities.

FREQUENT USERS OF EMERGENCY MEDICAL SERVICES IN A METROPOLITAN CITY: INDIVIDUAL- AND SYSTEM-LEVEL CONSIDERATIONS

Frequent 911 calls from older adults place a significant burden on emergency response systems. Drawing from key informant interviews, we explore factors implicated in repeated Emergency Medical Services (EMS) among older people in the City of Los Angeles and provide system and policy recommendations to mitigate overuse of EMS 911 calls. Los Angeles Fire Department (LAFD) dispatch call records documented 370,016 EMS encounters from 202,471 unique individuals over 50 from 2012 to 2016. Frequent 911 callers over the age of 50 (n=8), family members (n=6), Los Angeles Fire Department (LAFD) personnel (n=10), and community service providers (n=3) participated in in-depth, qualitative interviews to understand individual- and system-level factors that increase the likelihood of repeated calls. All interviews were audio recorded, transcribed, and analyzed thematically. Guided by Grounded Theory, two themes emerged across all interviewee groups pointing to factors that contributed to 911 calls: 1) The Nature of 911 Calls; 2) Barriers to Access. Patients and family members were aligned on a third theme: 3) Previous Encounters: Interactions with emergency care providers, while LAFD and service providers were in agreement on a fourth theme: 4) The Role of EMS Responders and Community Providers. All groups provided recommendations for the theme, 5) Change the System so that 911 calls do not serve as the default choice. Findings demonstrate the need to improve coordination between LAFD, medical and human service providers. Care coordination can support individual- and system-level supports for patients and families to address their needs and reduce repeated EMS use.

RACIAL/ETHNIC DISPARITIES IN RISK AND PROTECTIVE FACTORS OF DEMENTIA: A LIFESPAN APPROACH

We examined risk and protective factors associated with dementia and decomposed racial/ethnic disparities in factors associated with dementia. We performed a retrospective analysis of 3,495 individuals 65+ who participated in the 2016 Harmonized Cognitive Assessment Protocol, linked to Health and Retirement Study. Using the MMSE score, individuals were classified as having dementia vs cognitively normal. Risk factors included cardiovascular factors and hearing loss in midlife, current smoking, depression, and physical inactivity. Protective factors included educational attainment and wealth. Using Oaxaca-Blinder decomposition we quantified the relative contribution of individual variables in explaining racial/ethnic disparities. We found that Blacks and Hispanics have higher dementia risk compared to Whites. Accounting for demographics, mid-and later-life risk and protective factors explained one-third of the difference in Blacks and Whites’ cognitive functioning, and two-thirds of the difference in Hispanics and Whites. The findings highlight disparate dementia rates, and the need to elucidate other factors beyond race/ethnicity.

ASSOCIATIONS BETWEEN COVID-19 PERCEPTIONS AND PREVENTIVE BEHAVIORS IN DEMENTIA CAREGIVING DYADS

This study adopted a dyadic perspective to examine how the perceptions of COVID-19 (i.e., anxiousness & hopefulness) of dementia caregiving dyads are associated with their engagement in personal (e.g., washing hands, wearing mask) and social (e.g., avoiding physical contact and going restaurants/bars) preventive behaviors. Multiple cross-sectional Actor-Partner Interdependence Models (APIMs) were estimated using data from the 2020 NHATS/NSOC COVID-19 Supplements (N=1565). In the anxiousness models, participants’ own feeling of anxiousness was associated with their own engagement in personal preventive behaviors (actor effects), and the perceived anxiousness of PLWD was associated with personal preventive behaviors of caregivers (partner effect). In the model on social preventive behaviors, both actor and partner effects were found on dementia caregiving dyads. No effect was found in the models on hopefulness. Our findings extend understandings of mutual influence within the caregiving dyads and demonstrate the possibility of developing interventions for caregivers to promote PLWD’s health behaviors.

ORGANOCHLORINE EXPOSURES AND COGNITIVE FUNCTION IN OLDER LIFE: THE ROLE OF RACE/ETHNICITY

Organochlorines (OCs) are persistent pesticides that remain in the environment and body for extended periods after exposure. Little is known about their long-term impact on cognition in later life. Some studies, but not all, have shown that higher levels of selected OCs are associated with lower cognitive function (CF). Using weighted linear generalized estimating equations, we explored whether the association between lipid-adjusted levels of 8 OCs and global CF is modified by race/ethnicity in 985 adults age 60+ from the National Health and Nutrition Examination Surveys (2011-2014). Adjusting for covariates, results indicated that higher levels of grouped-OCs are not associated with lower CF (p=0.121), but higher levels of specific OCs were associated with lower CF: Mirex[p=0.029]; Oxychlordane[p=0.036]; p,p’-DDE[p=0.009]; p,p’-DDT[p=0.003]; and trans-Nonachlor[p=0.023]. These associations did not differ by race/ethnicity. Disentangling the complex impact of OCs on late-life cognition—whether in combination or singularly—may lead to more equitable environmental health policies.

ACCULTURATION ON PSYCHOLOGICAL DISTRESS AMONG OLDER KOREAN AMERICANS: DOES ETHNIC COMMUNITY SOCIAL CAPITAL MATTER?

Responding to the rapid growth of the older immigrant population and building upon the literature on the critical role of acculturation in older immigrants’ health and well-being, we focused on the role of ethnic community social capital (social cohesion, social engagement, safety, and negative interactions in ethnic communities) in older Korean Americans. Guided by social capital and stress-buffering theories, we examined the direct effect of acculturation and ethnic community social capital on psychological distress, as well as their interactions. We hypothesized that the negative impact of low acculturation on mental health would be lowered by positive perceptions of and experiences in ethnic communities. Using data from 2,150 participants in the Study of Older Korean Americans (Age range = 60-99, M [SD] = 73.4 [7.97]), the direct and interactive effect models were examined. Results showed that low acculturation posed a significant risk to mental health and all four types of ethnic community social capital had a significant direct effect. Furthermore, significance was observed in the interaction of acculturation with social cohesion (B [SE] = .01 [.01]. p < .05) and with negative interaction (B [SE] = -.01 [.01]. p < .01). The negative impact of low acculturation was attenuated among those with a high sense of ethnic community social cohesion but intensified among those with frequent experiences of negative interactions with ethnic community members. Our findings highlight the importance of social capital that forms within ethnic communities and provide implications for programs and services to promote older immigrants’ mental well-being.

Salt marsh fragmentation in a mesotidal estuary: Implications for medium to long-term management

During the last decades many salt marshes worldwide have suffered important losses in their extent and associated ecosystem services. The salt marshes of San Vicente de la Barquera estuary (N Spain) are a clear example of this, with a drastic reduction in vegetation surface over the last 60 years. This paper provides insights into the main factors controlling salt marsh functioning in sheltered estuarine areas. Regional and local factors have been disaggregated to identify the main drivers controlling the functioning of the salt marsh to develop appropriate management measures according to the evolution of the system. These factors have been studied in their spatial context through detailed maps of change in vegetation cover combined with topographic data obtained from UAV and RTK-DGPS surveys. The results demonstrate that in this estuary the salt marsh area is declining following a fragmentation process. No clear pattern of vegetation loss/gain with elevation has been identified. However, the results point to increased hydrodynamic stress in the area, with stronger currents inside the estuary. This is probably the major factor responsible for the decline of the salt marshes in the San Vicente de la Barquera estuary. Furthermore, several human interventions during the 20th century (local drivers) have also probably contributed to a lower resilience against SLR (regional driver). This work demonstrates that both natural and human drivers of change need to be considered when characterizing the evolution of salt marshes, wherever efficient management strategies need to be designed.

Duration of Dementia and Social Service Use in the U.S.-Born and Foreign-Born Mexican-American Population

Objective

The study estimates the number of years after age 65 that Mexican Americans live with likely dementia and the impact of dementia on community-based services (CBS) use by nativity.

Methods

Using the Hispanic Established Populations for the Epidemiologic Studies of the Elderly Sullivan methods are employed to predict duration of dementia and logistic regressions identify the predictors of service utilization.

Results

Foreign-born women spend more years than other groups with dementia. The foreign-born are more likely to use out-of-home services, whereas U.S.-born are more likely to use in-home services. The foreign-born with dementia of relatively recent onset had the highest probability of service use.

Discussion

Given the high cost of institutional care and availability of family caregivers, community-based services are a potentially useful alternative for the growing Mexican-American population living with dementia. Expanded Medicaid and CBS programs could be an equitable and cost-effective alternative that should be investigated.

Colorimetric Detection of Sepsis-Derived Hyperdegranulation with Plasmonic Nanosensors

Hyperdegranulation of neutrophilic granulocytes is a common finding in sepsis that directly contributes to the heightened immune response leading to organ dysfunction. Currently, cell degranulation is detected by flow cytometry, which requires large infrastructure that is not always available at the point of care. Here, we propose a plasmonic assay for detecting the degranulation status of septic cells colorimetrically. It is based on triggering the aggregation of gold nanoparticles with cationic granule proteins. Cells from septic patients contain fewer granules and therefore release less cationic proteins than healthy cells. This results in red-colored assays than can be easily detected by eye. The assay can selectively detect cationic granule proteins even in the presence of an excess of unrelated proteins, which is key to detect degranulation with high specificity. Coupling this signal generation mechanism with a magnetic purification step enabled the identification of septic cells with the same performance as flow cytometry. This makes the proposed method a promising alternative for diagnosing sepsis in decentralized healthcare schemes.

The Role of Secondary Care Networks, Gender, and Race on Primary Caregiver Burden

In addition to primary caregivers, many older adults receive care from secondary care networks (SCN), which include family members and friends. Literature rarely considers support that SCN provided to primary caregivers. This study examines: (a) the association between SCN support and primary caregiver burden, and (b) the intersectional effects of gender (male/female)-race (White/Black) identities of primary caregivers on the association. A cross-sectional study using data from 2015 National Health and Aging Trend Study (NHATS) and National Study of Caregiving (NSOC) was conducted. A total of 967 older adults, 967 primary caregivers, and 2253 secondary caregivers were selected. SCN support was measured by (a) care domain overlap, and (b) proportion of caregiving by SCN. Negative binomial regressions on overall and split samples estimated main effects of SCN support and the intersectional effects of gender and race. Both SCN-related variables were associated with primary caregiver burden, but significant three-way interaction was only found between gender, race, and proportion of caregiving by SCN. Black female caregivers reported heaviest burden and having SCN support was associated with lower risk of being burdened. Whereas Black male caregivers reported lightest burden and SCN support was not associated with their perceived burden. Our findings support the positive role of SCN in reducing stress of primary caregivers, and demonstrate that positive impacts of SCN support vary across gender-race groups. The results indicate a strong need for support programs aimed at promoting cooperation among family caregivers for burden reduction, especially families with female and Black primary caregivers.

Focus Group Findings of Trial Participants in a Caregiver Psychosocial Intervention: Savvy Caregiver Program

Previous work highlights the importance of sociobehavioral interventions to address dementia caregiving health and wellbeing outcomes. By empowering caregivers to become objective managers of their loved one’s illness, and own self-care, they are less likely to exhibit negative outcomes. We are conducting a mixed-method, randomized trial to test manualized, multi-family psychoeducational group interventions: Savvy Caregiver Express, and Savvy Caregiver Program. This poster describes the qualitative findings of four focus group interviews recently conducted to elucidate the study participation experiences of family caregivers enrolled in the parent study. Twenty-five racially and ethnically diverse participants (21 women, 4 men) caring for a family member with cognitive decline participated in focus group interviews conducted via videoconferencing methods. We captured more nuanced experiences from the perspective of study participants with regards to the caregiver interventions and their research participation. Interviews were conducted by trained research personnel, lasted 60-75 minutes, and followed an open-ended questioning route. Based on thematic analyses, we identified the following themes: 1) Changing one’s mindset: Seeing life through their shoes; 2) Getting information in one place; 3) Expanding the personal experience; 4) Fears and vulnerability; 5) Time constraints vs. wanting more; 6) Not everyone is at the same place; 7) Technology: It’s going to be part of our lives; and 8) Research: Not always in sync. Our findings indicate high satisfaction with most components of the program while specific recommendations were offered to improve the intervention and study experience such as tailoring materials to stage-specific needs.

Family Proximity as a Moderator of Spousal Associations of Depression among Mexican Older Adults

Depression among older adults is a public health issue, and a large literature highlights the importance of close relationships as both a risk and protective factor for depression. Research in U.S. samples suggests that one spouse’s depressive symptoms can increase their partner’s depressive symptoms, especially for women (Kouros & Cummings, 2010; Tower & Kasl, 1996). Little is known about interpersonal associations in depression, mitigating factors, and the role of gender among older couples in Mexico. This study examined (1) the effects of an individual’s depressive symptoms on their spouse’s symptoms and 2) whether living close to family buffered depression associations using data from the Mexican Health and Aging Study (n=4,071 dyads, age 50+ at initial interview). Depressive symptoms were measured in 2001, 2003, 2012, 2015, and 2018 using a modified 8-item version of the Center for Epidemiologic Studies-Depression Scale. Multilevel modeling was used to fit a dual-intercept growth model (centered at 2012) of husbands’ and wives’ depressive symptoms over time, controlling for age and education. Results showed a partner effect for husbands and wives, such that having a spouse with greater depressive symptoms in 2001 was associated with greater subsequent depressive symptoms, but not with rate of change in symptoms, in 2012. There was also a moderation effect such that the deleterious effect of husbands’ depressive symptoms on wives’ symptoms, as well as rate of increase in symptoms, was higher when family lived nearby, suggesting family may potentially exacerbate depression associations among spouses rather than a buffering them as hypothesized.

Cultural Adaptations to Recruitment Strategies and Community-Based Interventions for Dementia Caregivers

Nearly 30 years after the 1993 National Institute of Health Revitalization Act, minority groups’ low participation in research remains (which required the inclusion of women and racial/ethnic minority groups into government-funded clinical trials). This is particularly the case for participation in research on Alzheimer’s Disease and related dementias (ADRD). Deeply rooted historical race-based mistreatment in research and in the health care system at large persist as barriers to low-participation of minorities (i.e. Black/African American, Hispanic/Latino) and immigrants in research studies, who remain at disparate risk for adverse ADRD health outcomes and expedited mortality. The use of culturally adapted approaches in recruitment strategies and community-based interventions might be helpful to encourage the participation of underrepresented groups into research. As such, this presentation highlights three studies that seek to use cultural adaptation to inform recruitment strategies and community-based interventions. First, Dr. Parker will present how tenets from Critical Race Theory can be used to inform culturally-adapted recruitment strategies of Black/African American caregivers into community-based research by drawing upon two ongoing studies: a randomized trial providing caregiver support through Adult Day Services (ADS) and the evaluation of impact of ADS on stress levels of Black/African American using biomarker measures. Next, Ms. Johnson will present results on cultural adaptions to the ADS-Plus Program for Spanish-speaking populations. Finally, Dr. Nkimbeng will present on the process of culturally-tailoring dementia education for African immigrants in Minnesota. Findings from this presentation identify opportunities for researchers to use cultural adaptations to encourage participation of underrepresented populations into ADRD research.

Racial and Ethnic Differences in Risk and Protective Factors of Dementia and CIND in the United States

Recent population-based studies have shown declines in dementia prevalence in high-income countries, suggesting that improved population cardiovascular health and rising levels of education in the past 25 year were associated with reduction of dementia risks. However, in the US, there are variations in educational attainment, prevalence and management of chronic diseases, and behaviors associated with poor cardiovascular health among racial and ethnic groups. We performed a retrospective analysis of 3,495 older individuals (65+) in 2016 who participated in Harmonized Cognitive Assessment Protocol (HCAP) subsample of the Health and Retirement Study (HRS), to examine racial/ethnic differences in risk and protective factors associated with dementia and cognitive impairment. Linking HCAP to HRS, we traced individuals back to 2000 and created a longitudinal data of HCAP population (2000-2016). We found that racial/ethnic differences in risk and in protective factors throughout the life-course were associated with racial and ethnic disparities in dementia prevalence.

Low Albumin Levels Are Associated with Poorer Outcomes in a Case Series of COVID-19 Patients in Spain: A Retrospective Cohort Study

There is limited information available describing the clinical and epidemiological features of Spanish patients requiring hospitalization for coronavirus disease 2019 (COVID-19). In this observational study, we aimed to describe the clinical characteristics and epidemiological features of severe (non-ICU) and critically patients (ICU) with COVID-19 at triage, prior to hospitalization. Forty-eight patients (27 non-ICU and 21 ICU) with positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection were analyzed (mean age, 66 years, [range, 33–88 years]; 67% males). There were no differences in age or sex among groups. Initial symptoms included fever (100%), coughing (85%), dyspnea (76%), diarrhea (42%) and asthenia (21%). ICU patients had a higher prevalence of dyspnea compared to non-ICU patients (95% vs. 61%, p = 0.022). ICU-patients had lymphopenia as well as hypoalbuminemia. Lactate dehydrogenase (LDH), C-reactive protein (CRP), and procalcitonin were significantly higher in ICU patients compared to non-ICU (p < 0.001). Lower albumin levels were associated with poor prognosis measured as longer hospital length (r = −0.472, p < 0.001) and mortality (r = −0.424, p = 0.003). As of 28 April 2020, 10 patients (8 ICU and 2 non-ICU) have died (21% mortality), and while 100% of the non-ICU patients have been discharged, 33% of the ICU patients still remained hospitalized (5 in ICU and 2 had been transferred to ward). Critically ill patients with COVID-19 present lymphopenia, hypoalbuminemia and high levels of inflammation.

A Type 1 Diabetes Genetic Risk Score Predicts Progression of Islet Autoimmunity and Development of Type 1 Diabetes in Individuals at Risk

OBJECTIVE

We tested the ability of a type 1 diabetes (T1D) genetic risk score (GRS) to predict progression of islet autoimmunity and T1D in at-risk individuals.

RESEARCH DESIGN AND METHODS

We studied the 1,244 TrialNet Pathway to Prevention study participants (T1D patients' relatives without diabetes and with one or more positive autoantibodies) who were genotyped with Illumina ImmunoChip (median [range] age at initial autoantibody determination 11.1 years [1.2-51.8], 48% male, 80.5% non-Hispanic white, median follow-up 5.4 years). Of 291 participants with a single positive autoantibody at screening, 157 converted to multiple autoantibody positivity and 55 developed diabetes. Of 953 participants with multiple positive autoantibodies at screening, 419 developed diabetes. We calculated the T1D GRS from 30 T1D-associated single nucleotide polymorphisms. We used multivariable Cox regression models, time-dependent receiver operating characteristic curves, and area under the curve (AUC) measures to evaluate prognostic utility of T1D GRS, age, sex, Diabetes Prevention Trial-Type 1 (DPT-1) Risk Score, positive autoantibody number or type, HLA DR3/DR4-DQ8 status, and race/ethnicity. We used recursive partitioning analyses to identify cut points in continuous variables.

RESULTS

Higher T1D GRS significantly increased the rate of progression to T1D adjusting for DPT-1 Risk Score, age, number of positive autoantibodies, sex, and ethnicity (hazard ratio [HR] 1.29 for a 0.05 increase, 95% CI 1.06-1.6; P = 0.011). Progression to T1D was best predicted by a combined model with GRS, number of positive autoantibodies, DPT-1 Risk Score, and age (7-year time-integrated AUC = 0.79, 5-year AUC = 0.73). Higher GRS was significantly associated with increased progression rate from single to multiple positive autoantibodies after adjusting for age, autoantibody type, ethnicity, and sex (HR 2.27 for GRS >0.295, 95% CI 1.47-3.51; P = 0.0002).

CONCLUSIONS

The T1D GRS independently predicts progression to T1D and improves prediction along T1D stages in autoantibody-positive relatives.

Psychosocial Approaches for Sexual Health and Intimate Relationships Among Patients With Serious Mental Illness

INTRODUCTION

The sexual health and behavior and the intimate relationships of patients diagnosed with a serious mental illness (SMI) have been described as ongoing and often ignored concerns in mental health treatment. Evidence-based psychosocial interventions have emerged as effective complimentary approaches to address symptoms of SMI in conjunction with psychopharmacology, yet rarely do they address sexual concerns in a targeted manner.

AIM

This systematic review explores the scope and efficacy of psychosocial interventions designed to address sexual health and behavior and intimate relationship concerns in patients with SMI.

METHODS

The search was conducted in four targeted databases and identified 967 articles with four of those meeting inclusion criteria for this review.

MAIN OUTCOME MEASURES

The data extracted included setting, study sample, study design, outcome measures, data analysis, and results. The measures utilized in the studies assess mental and sexual health-related outcomes.

RESULTS

All four studies reported an improvement in sexual and mental health outcomes.

CONCLUSION

Given the lack of psychosocial approaches and culturally sensitive adaptations, this review highlights a gap in literature that should be addressed, particularly emphasizing their combined treatment with psychotropic medication and efficacy testing with diverse populations.

Low-dose radiation hyper-radiosensitivity in multicellular tumour spheroids

OBJECTIVE

We propose and study a new model aimed at describing the low-dose hyper-radiosensitivity phenomenon appearing in the survival curves of different cell lines.

METHODS

The model uses the induced repair assumption, considering that the critical dose at which this mechanism begins to act varies from cell to cell in a given population. The model proposed is compared with the linear-quadratic model and the modified linear-quadratic model, which is commonly used in literature and in which the induced repair is taken into account in a heuristic way. The survival curve for the MCF-7 line of human breast cancer is measured at low absorbed doses and the uncertainties in these doses are estimated using thermoluminiscent dosemeters.

RESULTS

It is shown that these multicellular spheroids present low-dose hyper-radiosensitivity. The new model permits an accurate description of the data of two human cell lines (previously published) and of the multicellular spheroids of the MCF-7 line here measured.

CONCLUSION

The model shows enough flexibility to account for data with very different characteristics and considers in a faithful way the hypothesis of the repair induction.

Visual Control for Multirobot Organized Rendezvous

This paper addresses the problem of visual control of a set of mobile robots. In our framework, the perception system consists of an uncalibrated flying camera performing an unknown general motion. The robots are assumed to undergo planar motion considering nonholonomic constraints. The goal of the control task is to drive the multirobot system to a desired rendezvous configuration relying solely on visual information given by the flying camera. The desired multirobot configuration is defined with an image of the set of robots in that configuration without any additional information. We propose a homography-based framework relying on the homography induced by the multirobot system that gives a desired homography to be used to define the reference target, and a new image-based control law that drives the robots to the desired configuration by imposing a rigidity constraint. This paper extends our previous work, and the main contributions are that the motion constraints on the flying camera are removed, the control law is improved by reducing the number of required steps, the stability of the new control law is proved, and real experiments are provided to validate the proposal.

In vivo hepatic oxidative stress because of carbon tetrachloride toxicity: protection by melatonin and pinoline

The protective in vivo effects of melatonin or pinoline on carbon tetrachloride (CCl(4))-induced oxidative damage were investigated in liver of rats and compared to rats injected only with CCl(4) (5 mL/kg body weight). Hepatic cell membrane fluidity, monitored using fluorescence spectroscopy, exhibited a significant decrease in animals exposed to CCl(4) compared to control rats. Increases in lipid and protein oxidation, as assessed by concentrations of malondialdehyde (MDA) and 4-hydroxyalkenals (4-HDA), and protein carbonylation, respectively, were also seen in hepatic homogenates of animals exposed to CCl(4). The administration of melatonin (10 mg/kg body weight) or pinoline injected 30 min before and 1 hr after CCl(4), fully prevented membrane rigidity and protein oxidation. However, treatment with melatonin was more effective in terms of reducing lipid peroxidation than pinoline, as the increases in MDA+4-HDA levels because of CCl(4) were reduced by 93.4% and 34.4% for melatonin or pinoline, respectively. Livers from CCl(4)-injected rats showed several histopathological alterations; above all, there were signs of necrosis and ballooning degeneration. The concurrent administration of melatonin or pinoline reduced the severity of these morphological changes. On the basis of the biochemical and histopathological findings, we conclude that both melatonin and pinoline were highly effective in protecting the liver against oxidative damage and membrane rigidity because of CCl(4). Therefore, these indoles may be useful as cotreatments for patients with hepatic intoxication induced by CCl(4).

Managing depression in home health care: a randomized clinical trial

A prospective randomized trial was conducted to examine the effectiveness, feasibility, and degree of implementation of home health care quality improvement interventions when implemented under usual conditions by usual care providers. A total of 311 older adults were randomized to enhanced usual care (EUC) that included routine depression screening and staff training in depression care management for older adults or to the intervention group (INT) that included antidepressants and/or psychotherapy treatment plus EUC. Implementing a routine screening protocol using the PHQ-9 and depression care management quality improvements is feasible in diverse home health care organizations and results in consistently better (but not statistically significant) depression outcomes in the INT group.

Routine PHQ-9 depression screening in home health care: depression, prevalence, clinical and treatment characteristics and screening implementation

This study aimed to examine: the prevalence and correlates of depression among adults age 65 and over on admission to diverse home health care programs; nurse compliance with routine screening using the PHQ-9; and concordance between the number of depressed individuals identified by the PHQ-9 and Medicare-mandated nursing assessment following targeted nurse training in identifying depression among the elderly using a standard diagnostic screen. Data are drawn from routine screening of 9,178 patients (a 77% screening compliance rate). Of all patients screened, 782 (8.5%) met criteria for probable major depression and 148 (1.6%) for mild depression. Concordance between nurse identified depression via PHQ-9 and OASIS depression assessment improved over that reported in previous studies. Findings suggest that the use of a routine screening tool for depression can be implemented with minimal in-house training and improves detection of depression among older adults with significant physical and functional impairment.

Health-related quality of life in HIV-infected naive patients treated with nelfinavir or nevirapine associated with ZDV/3TC (the COMBINE-QoL substudy)

PURPOSE

The aim of the study was to assess differences in health-related quality of life (HRQoL) in HIV-infected naive patients treated with two HAART regimens at 12 months.

METHOD

The MOS-HIV questionnaire was used to measure HRQoL in a subgroup of 127 patients included in the COMBINE study, which was an open-label, randomized, multicenter study comparing zidovudine (ZDV) and lamivudine (3TC) plus nelfinavir (NFV) or nevirapine (NVP) regimens in HIV-infected naive patients. 63 patients were included in the ZDV/3TC/NFV arm and 64 in the ZDV/3TC/NVP arm.

RESULTS

No statistically significant differences were observed at baseline in demographic and clinical variables and HRQoL scores between treatment groups, except that the proportion of homosexual men was higher in the ZDV/3TC/NVP arm. There were no statistically significant differences in HRQoL scores between arms at 12 months and over time; only ZDV/3TC/NVP patients showed statistically significant improvement in Physical Health Summary score (p <.01) and a trend toward a better profile in Mental Health Summary score (p =.07). Overall, patients who were treated with ZDV/3TC/NVP showed greater changes in physical dimensions and patients who were treated with ZDV/3TC/NFV showed greater changes in mental health.

CONCLUSION

Differences in HRQoL between study groups at 1 year follow-up were not detected. Nevertheless, a trend toward improvement was observed in summary health scores in ZDV/3TC/NVP-treated patients.

Inhaled nitric oxide and pulmonary vasoreactivity

Inhaled nitric oxide is a ubiquitous molecule which is produced endogenously and is also found in air pollution and in cigarette smoke. After describing the chemistry of NO, we review its history from the first description in 1980 to the current clinical indications. The biosynthesis of NO, its effects on pulmonary vasoreactivity, and the administration of inhaled NO will be described. The indications, uses, and side effects of inhaled NO are discussed with an emphasis on withdrawal of NO therapy, specifically the "rebound" phenomenon. Possible drug interactions are listed. Inhaled nitric oxide is here to stay, and future studies will provide more information on its therapeutic dose, duration and potential toxicity.

Dose dependence of the growth rate of multicellular tumour spheroids after irradiation

The present study investigated differences in the growth rate of multicellular tumour spheroids of the MCF-7 line of human breast cancer before and after their irradiation. Growth of the spheroids was analysed according to a model based on a Gompertz function. In this model, normalization to a common initial volume is achieved in a way that enables meaningful comparisons to be made between the results obtained for each spheroid. For irradiated spheroids the model includes an additional term to take account of sterilized cells. We found that the growth rate observed before irradiation is not fully recovered by irradiated spheroids and that growth recovery reduces with higher irradiation doses. Surviving fractions obtained at doses below 3 Gy are comparable with those found in clonogenic assays on spheroids of the same cellular line. At larger doses, discrepancies between the different studies are considerable.

Stress and depressive symptoms among Mexican American elders

Although social stressors have successfully predicted depressive symptomatology in a number of populations, few studies have examined the relevance of stressors for Mexican American elders. Results are reported here from a multistage probability sample of 3,050 Mexican Americans aged 65 and older drawn from a 5-state region. Participants reported low levels of education and income, and most reported difficulty in reading or writing in English. Deaths, illness of close other, and financial problems were the three most frequent life events, and many reported financial strains. Depressive symptoms were then regressed on demographic indicators, cognitive status, linguistic acculturation, social supports, and three types of stressors. Being a woman, lower income, decreased income, chronic financial strain, and several health stressors were associated with greater symptomatology. Results identified a cluster of economic stressors and conditions that may play a critical role in the etiology of depressive symptoms in this minority population.

Altered directionality in the Cre-LoxP site-specific recombination pathway

The site-specific recombinase Cre must employ control mechanisms to impose directionality on recombination. When two recombination sites (locus of crossing over in phage P1, loxP) are placed as direct repeats on the same DNA molecule, collision between loxP-bound Cre dimers leads to excision of intervening DNA. If two sites are placed as inverted repeats, the intervening segment is flipped around. Cre catalyzes these reactions in the absence of protein co-factors. Current models suggest that directionality is controlled at two steps in the recombination pathway: the juxtaposition of loxP sites and the single-strand-transfer reactions within the synaptic complex. Here, we show that in Escherichia coli strain 294-Cre, directionality for recombination is altered when the expression of Cre is increased. This leads to deletion instead of inversion on substrates carrying two loxP sites as inverted repeats. The nucleotide sequence composition of loxP sites remaining in aberrant products indicates that site alignment and/or DNA strand transfer in the in vivo Cre-loxP recombination pathway are not always tightly controlled.

Radiofrequency sacroiliac joint denervation for sacroiliac syndrome

BACKGROUND AND OBJECTIVES

Radiofrequency (RF) denervation of the sacroiliac (SI) joint has been advocated for the treatment of sacroiliac syndrome, yet no clinical studies or case series support its use.

METHODS

We report the results of a consecutive series of 50 SI joint RF denervations performed in 33 patients with sacroiliac syndrome. All patients underwent diagnostic SI joint injections with local anesthetic before denervation. Changes in visual analog pain scores (VAS), pain diagrams, physical examination (palpation tenderness over the joint, myofascial trigger points overlying the joint, SI joint pain provocation tests, and range of motion of the lumbar spine), and opioid use were assessed pre- and postdenervation.

RESULTS

The criteria for successful RF denervation were at least a 50% decrease in VAS for a period of at least 6 months; 36.4% of patients (12 of 33) met these criteria. Failure of denervation correlated with the presence of disability determination and pain on lateral flexion to the affected side. The average duration of pain relief was 12.0 +/- 1.2 months in responders versus 0.9 +/- 0.2 months in nonresponders (P < or = 0.0001). A positive response was associated with an atraumatic inciting event. Successful denervation was associated with a change in the pain diagram and a reduction in the pattern of referred pain, a normalization of SI joint pain provocation tests, and a reduction in the use of opioids.

CONCLUSIONS

This study suggests that RF denervation of the SI joint can significantly reduce pain in selected patients with sacroiliac syndrome for a protracted time period. Moreover, certain abnormal physical findings (i.e., SI joint pain provocation tests) revert to normal for the duration of the analgesia.

Comparison of twice-daily stavudine plus once- or twice-daily didanosine and nevirapine in early stages of HIV infection: the scan study

OBJECTIVES

To evaluate the safety and effectiveness of once-daily didanosine and nevirapine plus twice-daily stavudine versus twice-daily administration of all three drugs.

METHODS

This open-label, randomized, multicentre study enrolled 94 antiretroviral-naive patients with chronic HIV infection, CD4+ cell counts > 500 x 10(6) cells/l, and viral loads > 5000 copies/ml. Patients were treated with either 40 mg stavudine (twice daily) plus 400 mg didanosine (once daily) and 400 mg nevirapine (once daily) or 40 mg stavudine (twice daily) plus 200 mg didanosine (twice daily) and 200 mg nevirapine (twice daily).

RESULTS

After 12 months, 68% of patients who received twice-daily didanosine and nevirapine had viral loads < 200 copies/ml in the intention-to-treat and 79% in the on-treatment analysis, respectively. The corresponding values for patients treated with didanosine and nevirapine, taken once-daily, were 73 and 85%. The percentages of patients in each group with viral loads < 5 copies/ml at 12 months were 40% (once daily ) and 45% (twice daily) for the intention-to-treat analysis. Five of 11 patients (45%) with plasma viral loads < 5 copies/ml at 12 months had detectable virus in tonsillar tissue. Genotypic resistance to nevirapine was noted in seven of the 14 patients with detectable viral load at month 12. Mean changes in CD4+ cell counts for patients treated with stavudine plus once- or twice-daily didanosine and nevirapine were 154 and 132 x 10(6) cells/l, respectively. Treatment was interrupted due to adverse events in seven patients (8%) (four who received once-daily didanosine and nevirapine and three treated with twice-daily doses).

CONCLUSIONS

The combination of twice-daily stavudine plus once-daily didanosine and nevirapine was as safe and well tolerated as twice-daily administration of all three agents. Both regimens were equally effective in reducing viral loads and in increasing CD4+ cell counts.

Assessment of in vitro mutagenicity in Salmonella and in vivo genotoxicity in mice of the mycotoxin fumonisin B(1)

Fumonisin B(1) (FB(1)), a mycotoxin produced by Fusarium moniliforme, is a contaminant of cereals with various and complex cellular effects. FB(1) induces liver cancer in rats and has been linked to esophageal cancer in South Africa and China. The mechanisms of FB(1)-induced carcinogenesis are uncertain and the information on FB(1) mutagenic properties is limited and controversial. FB(1) contamination levels in maize and wheat from Chile were found to be similar to those in other countries. FB(1) was devoid of activity in gene mutation assays with Salmonella typhimurium strains TA100, TA102 and TA98. However, i.p. injection of FB(1) induced an increased frequency of micronuclei in mouse bone marrow polychromatic erythrocytes at 25 and 100 mg/kg. We conclude that FB(1) induces in vivo genotoxicity in the absence of in vitro mutagenicity in Salmonella.

Detection and localization of pulmonary air leaks using laser-polarized (3)He MRI

Pulmonary air leaks were created in the lungs of Yorkshire pigs. Dynamic, 3D MRI of laser-polarized (3)He gas was then performed using a gradient-echo pulse sequence. Coronal magnitude images of the helium distribution were acquired during gas inhalation with a voxel resolution of approximately 1.2 x 2.5 x 8 mm, and a time resolution of 5 sec. In each animal, the ventilation images reveal focal high-signal intensity within the pleural cavity at the site of the air leaks. In addition, a wedge-shaped region of increased parenchymal signal intensity was observed adjacent to the site of the air leak in one animal. (3)He MRI may prove helpful in the management of patients with pulmonary air leaks.

Anesthetics, sedatives, and paralytics. Understanding their use in the intensive care unit

This article reviews the use of inhalational, intravenous, and epidural agents used in the operating room and ICU. An emphasis is placed on the rationale for their selection. Additionally, the side effects and expected complications are discussed. By developing expertise with one's own repertoire of sedatives, narcotics, and neuromuscular blocking agents, one may decrease postoperative complications and lengths of stay.

Methyl bromide decreases excitability without having immediate toxic effects in rat hippocampal CA1 neurons in vitro

Methyl bromide, a disinfectant gas amply used worldwide, is neurotoxic in humans and other mammals. To study its short-term effects on neurons, it was applied in aqueous solution to hippocampal slices of young rats (1.4 and 0.7 mM; for 8 minutes). Extracellular field recordings and intracellular microelectrode recordings from CA1 pyramidal neurons showed that the neurons stay viable for at least one hour after application of the mono-halomethane. However, a moderate, but consistent, irreversible decrease in synaptic excitability was observed. The intracellular recordings indicate that this may be attributed to a decrease in excitatory postsynaptic potentials. No effects were observed at 0.7 mM methyl bromide. Bromide, in a dose-dependent, partly reversible manner (during one hour), produced a similar decrease in excitability. Quantitatively, the action of bromide at 0.5 mM resembled the one seen with methyl bromide at the concentration of 1.4 mM. Since methyl bromide did not induce electrophysiologic changes consistent with evidence of neurotoxicity during one hour of observation it is concluded that it lacks immediate toxic effects on hippocampal rat neurons. Its neurotoxicity may be entirely due to metabolites or other indirect effects. The slight decrease in excitability may be due to the effect of bromide that is set free as tissue proteins and other cell molecules are methylated.

Combined therapy with inhaled nitric oxide and intravenous vasodilators during acute and chronic experimental pulmonary hypertension

Both inhaled nitric oxide (NO) and IV vasodilators decrease pulmonary hypertension, but the effects of combination therapy are unknown. We studied the response to inhaled NO (100 ppm) alone, IV vasodilator alone, and combined therapy during acute (U46619-induced) and chronic (monocrotaline-induced) pulmonary hypertension in the pentobarbital-anesthetized rat. Vasodilator doses were 1.0, 3.2, 10, and 32 microg x kg(-1) x min(-1) sodium nitroprusside (SNP); 50, 100, 150, 200, and 300 microg x kg(-1) x min(-1) adenosine; or 25, 50, 150, 200, and 300 ng x kg(-1) x min(-1) prostacyclin. In the absence of IV vasodilator therapy, inhaled NO decreased mean pulmonary artery pressure without decreasing mean systemic arterial pressure. In both acute and chronic pulmonary hypertension, the addition of inhaled NO to the largest dose of adenosine or prostacyclin, but not of SNP, decreased pulmonary artery pressure. Because inhaled NO and SNP activate guanylyl cyclase and adenosine and prostacyclin activate adenylyl cyclase, the results suggest that adding inhaled NO to a vasodilator not dependent on guanylyl cyclase may produce additional selective pulmonary vasodilation.

IMPLICATIONS

In therapy of pulmonary hypertension, inhaled nitric oxide should produce additional selective pulmonary vasodilation when combined with a vasodilator whose mechanism of action is not dependent on cyclic guanosine 3',5'-monophosphate.

Rabies in skunks from Mexico

An enzootic focus of rabies in skunks in Mexico is described. Fifty three wild animals including two badgers (Taxidea taxus), 32 bats (various species), one bobcat (Lynx rufus), two coatis (Nasua narica) three foxes (Urocyon cineroargenteus), one raccoon (Procyon lotor) and 12 skunks (see below) were tested for rabies by direct immunofluorescence assay from 1991 to 1997 in the central part of San Luis Potosi State, Mexico. Rabies occurrence was 21% of all tested mammals, with 19% in skunks and only 2% in other wild species (one bobcat). Skunks represented 23% of all mammals tested and had a rabies prevalence of 83%. Only 10 individuals were identified: three hog-nosed skunks (Conepatus leuconotus) and seven spotted skunks (Spilogale putorius). All were involved in human attacks; the spotted skunk attacks were inside bedrooms while people were sleeping, and the hog-nosed skunk attacks occurred outdoors. Skunk cases of rabies represented 40% of all rabies cases in 1997, and 100% of cases registered for wild animals in San Luis Potosi state. This situation constitutes an important public health problem and requires further epidemiological research to make the human population aware of the problem and to establish measures to limit further human attacks by rabid skunks.

Diagnostic utility of postmortem fine-needle aspiration cultures

BACKGROUND

Microbiological cultures at autopsy have not proved to be very useful. In life, transthoracic and fine-needle aspirations of other tissues have provided better results. The aim of this prospective study was to assess the diagnostic utility of postmortem cultures obtained by fine-needle aspiration puncture (FNAP) of several tissues when punctures were performed in the immediate postmortem period.

METHODS

Comparative analysis was performed between FNAP cultures and those obtained in life and by conventional autopsy. All adult autopsied patients who died at a general teaching hospital in a 3-year period were included. Clinical data, microbiological cultures before death, and pathologic data from autopsies of all patients were recorded, as were results of FNAP performed after death from the heart, right lower lung, liver, spleen, and other areas suspicious for infection. Cultures from the same sites were made at autopsy. Microorganisms were isolated and defined as infectious agents, colonizers, or contaminants according to standard criteria.

RESULTS

Ninety-two patients (59 men, 33 women) were included in the study; patients had a mean age of 67.7 years. There were five main diagnostic groups: neoplastic (n = 25), digestive (n = 15), respiratory (n = 14), circulatory (n = 10), and infectious diseases (n = 10). Infection was suspected in 47 patients (51.3%). Autopsy was performed 12 hours after death or later in 61% of patients. No significant differences were found in terms of contamination or colonization in relation to time between death and FNAP, time between death and autopsy, or microorganisms isolated. The sensitivity of FNAP and autopsy with respect to the isolation of infective microorganisms was similar (80.9% vs 87%), but FNAP was more specific (66.7% vs 44.4%). Age, sex, time between death and FNAP, clinical diagnosis, cause of death, and antimicrobial therapy did not influence the results significantly. Blood cultures gave the best results (specificity 84.4%) [corrected].

CONCLUSIONS

Fine-needle aspiration puncture performed in the immediate postmortem period adds relevant microbiological information to the clinicopathologic picture and provides higher specificity than autopsy cultures. Blood cultures are especially useful. When difficulties are associated with autopsy examination or in cases of selected clinical conditions, FNAP can be an effective tool for the postmortem diagnosis of infection.

[Mutations of the p53 suppressor gene in gastric adenocarcinoma]

BACKGROUND

We have shown numeric alterations such as hyperploidy and hypoploidy with loss of chromosome 17 in primary gastric cancer. This chromosome maps p53 suppressor gene that induces the transcription of genes related to cellular cycle control, DNA synthesis and repair, cellular differentiation and apoptosis.

AIM

To analyze, at a molecular level, the possible alterations of p53 suppressor gene in samples of gastric cancer and non tumoral mucosa.

MATERIAL AND METHODS

Tissue samples of gastric carcinoma and non tumoral gastric mucosa coming from 26 patients subjected to a total gastrectomy were analyzed. The mutation of p53 suppressor gene exons 7 to 9 were determined using a conformational polymorphism analysis in single strands of the gene and indirect sequencing in some cases.

RESULTS

Alterations in p53 gene were found in 77% of tumoral and 19% of non tumoral samples. T insertions in codons 260, 317 and 321, G insertion in codon 328 and G-T transvertion in codon 302 were found. Aminoacid sequence analysis of p53 protein obtained with sequencing data showed that T insertion in codon 260 could translate three erroneous aminoacids after the mutation and produce a truncated protein due to the creation of a stop codon. No associations between alterations of p53 gene and clinical or pathological variables such as age, sex, tumor localization, histological type and presence of lymph node metastases were observed.

CONCLUSIONS

Mutations of p53 suppressor gene are frequent in gastric carcinoma.