Lore K. Wright

Moderating and mediating effects in causal models.

This article explains causal relationships in conceptual models of mental health phenomena. Direct, moderating, mediating, and reciprocal effects among variables are defined, appropriate statistical analyses are described, and the correct interpretations of moderating versus mediating effects are discussed. Examples are provided that will help the reader to distinguish between moderating and mediating effects.

Affection and Sexuality in the Presence of Alzheimer's Disease: A Longitudinal Study

Affection and sexuality were studied longitudinally for two groups of couples, one with an Alzheimers disease (AD) afflicted spouse and the other spouse the primary caregiver, and a second group with both spouses relatively healthy. Affectional expressions were not different for the two groups prior to illness onset but declined significantly for the AD group five years into the illness trajectory; affection remained stable for the well group. Based on follow-up data obtained two years later, outcomes for afflicted spouses were taken into consideration, and the pattern for affection was be reexamined. Affection increased significantly after nursing home placement of an ill spouse.Fewer AD than well couples were sexually active five years into the illness trajectory. The problem of hypersexuality in a few male afflicted spouses had abated two years later. The number of well couples who were sexually active also declined over time, but several couples continued at the same or higher levels of sexual intimacy. The study contrasts normal aging from pathological deviations within a human developmental perspective.

Racial differences in health status and health behaviors of older adults

BACKGROUND Little is known about racial differences in health status and health behaviors of older adults, especially among the oldest old. OBJECTIVES To investigate racial differences in health status and health behaviors of African American and Caucasian older adults and to identify factors that influence health behaviors of older adults. METHOD A descriptive comparative study using data from the Georgia Centenarian Study was conducted. The subjects were 248 older adults (181 Caucasians and 67 African Americans) ranging in age from 60 to 107 years. Demographic characteristics, health status, and four health behaviors were assessed. RESULTS African Americans had significantly lower mental health (p < .001) and poorer self-perceived health (p < .01) than did their Caucasian counterparts; however, when covaried with education and income, racial differences in self-perceived health were eliminated, and differences in mental health decreased but remained significant (p < .05). Using univariate analyses, only two health behaviors, physical activity and eating breakfast regularly, showed significant racial differences. Relatively few older adults participated in leisure-time physical activity. Logistic regression analyses indicated that race was not significantly related to any health behaviors. Age, gender, and physical health status were most frequently related to health behaviors. CONCLUSION The findings indicated no robust racial differences in health status and health behaviors, especially when education and income were controlled. More research is recommended to clarify the factors that explain health behaviors of older adults.

Human Development in the Context of Aging and Chronic Illness: The Role of Attachment in Alzheimer's Disease and Stroke:

Does chronic illness in older people provide potentials for human development? To date, this question has not been adequately addressed by dynamic theorists of human development. In this article, two illness trajectories, Alzheimers disease and stroke, are examined to illustrate emerging changes in human development over each course of illness and the increasing importance of attachment behavior among ill elders and their family members. It is argued that the phenomenon of attachment links ailing older people to their environment, and that attachment is vital if human development is to continue.

Telecommunication interventions for caregivers of elders with dementia.

Caregiver Interventions via Telecommunications (CIT) is designed for family caregivers of elders with dementia. Building on Riegels dialectical theory of human development, the authors argue that psychotherapeutic interventions, made highly accessible by telecommunication technology, assist caregivers to achieve positive developmental outcomes. Specific components of CIT are described, and an outline for a structured protocol is provided. Advantages, disadvantages, and future directions of telecommunications therapy are discussed.

Dual Orientation of the Outer Membrane Lipoprotein P6 of Nontypeable Haemophilus influenzae

The majority of outer membrane (OM) lipoproteins in Gram-negative bacteria are tethered to the membrane via an attached lipid moiety and oriented facing in toward the periplasmic space; a few lipoproteins have been shown to be surface exposed. The outer membrane lipoprotein P6 from the Gram-negative pathogenic bacterium nontypeable Haemophilus influenzae (NTHi) is surface exposed and a leading vaccine candidate for prevention of NTHi infections. However, we recently found that P6 is not a transmembrane protein as previously thought (L. V. Michel, B. Kalmeta, M. McCreary, J. Snyder, P. Craig, M. E. Pichichero, Vaccine 29:1624-1627, 2011). Here we pursued studies to show that P6 has a dual orientation, existing infrequently as surface exposed and predominantly as internally oriented toward the periplasmic space. Flow cytometry using three monoclonal antibodies with specificity for P6 showed surface staining of whole NTHi cells. Confocal microscopy imaging confirmed that antibodies targeted surface-exposed P6 of intact NTHi cells and not internal P6 in membrane-compromised or dead cells. Western blots of two wild-type NTHi strains and a mutant NTHi strain that does not express P6 showed that P6 antibodies do not detect a promiscuous epitope on NTHi. Depletion of targets to nonlipidated P6 significantly decreased bactericidal activity of human serum. Protease digestion of surface-exposed P6 demonstrated that P6 is predominantly internally localized in a manner similar to its homologue Pal in Escherichia coli. We conclude that P6 of NTHi is likely inserted into the OM in two distinct orientations, with the predominant orientation facing in toward the periplasm.

Mental Health in Older Spouses: The Dynamic Interplay of Resources, Depression, Quality of the Marital Relationship, and Social Participation

This study demonstrates a conceptual linkage between exchange theory and psychoanalytic theory of depression. The effects of diminished resources and the dynamic relationships between depression, quality of the marital relationship, and social participation were investigated with a sample of 229 community residing, married older people (Duke Longitudinal Study) using a combined structural and measurement model with linear structural relations (LISREL) analysis. Findings are that some resources have direct effects on depression, marital quality, and social participation. However, it is through the pathway of depressive moods that ill health, retirement, and stress have their negative effects on the marital relationship. Depressive moods do affect social participation, but psychosomatic symptoms of depression do not affect the amount of social participation nor the marital relationship. Recognizing depressive moods as intervening variables is important because older people tend to deny feeling depressed. Without a conceptual linkage of exchange and depression theories, this pathway would not have been identified.

A nanoparticle-coated chemiresistor array as a microscale gas chromatograph detector for explosive marker compounds: flow rate and temperature effects

The effects of flow rate and temperature on the performance of a microscale gas chromatographic (μGC) detector consisting of a chemiresistor (CR) array coated with different thiolate-monolayer-protected gold nanoparticles (MPNs) are described with respect to the analysis of three gas-phase markers of the explosive trinitrotoluene (TNT): 2,4-dinitrotoluene (2,4-DNT), 2,6-dinitrotoluene (2,6-DNT), and 2,3-dimethyl-2,3-dinitrobutane (DMNB). In chamber tests, sensors were stable at 70 °C for several days in air, with <2% sensitivity drift per day and virtually no change in the array response patterns. In tests with a conventional upstream GC column, increasing the array temperature from 55-80 °C (1.2 mL min(-1)) led to similar (i.e., 4-6.6-fold) decreases in sensitivity, increases in the limits of detection (LODs), and increases in (estimated) chromatographic resolution. Increasing the flow rate from 1.1-3.7 mL min(-1) (70 °C) led to ∼1.3-2-fold decreases in sensitivity and LOD for 2,4-DNT and 2,6-DNT, a ∼2-fold net increase in LOD for DMNB (passes through a maximum), and a <2-fold increase in resolution. Results indicate that the rates of desorption of the marker vapors out of the MPN films are important determinants of observed trends. With Si-micromachined focuser/injector and separation column devices placed upstream of a CR array held at 70 °C, a mixture of the two primary markers, 2,4-DNT and DMNB, and four similarly volatile alkane interferents was separated in 1.5 min at 3 mL min(-1).

Screening to detect asymptomatic shedding of herpes simplex virus (HSV) in women with recurrent genital HSV infection.

To investigate the asymptomatic shedding of herpes simplex virus (HSV) from women with recurrent genital herpes infection, and to assess whether inapparent shedding could occur, eight such women were examined thrice weekly for one month. At each visit colposcopy was performed and multiple sites sampled for HSV. During the study four women had no recurrence of HSV infection, but four had at least one positive viral culture. One of these patients was asymptomatically shedding HSV on nine of her 11 clinic visits. Two episodes of urethral shedding were detected. In this group of patients the presence of inguinal lymphadenopathy was appreciably associated with the isolation of HSV from the urogenital tract.

Health Behavior of Caregivers

Approximately 8 million adult Americans provide personal care to an older, ill family member or close friend (Harper, 1991). These adults are known as “informal caregivers,” and many studies have documented that caregiving responsibilities put them at risk for emotional and physical health problems (Schulz, Visintainer, & Williamson, 1990; Wright, Clipp, & George, 1993).