"Going vaccine hunting": Multilevel influences on COVID-19 vaccination among racialized sexual and gender minority adults-a qualitative study

High levels of COVID-19 vaccine hesitancy have been reported among Black and Latinx populations, with lower vaccination coverage among racialized versus White sexual and gender minorities. We examined multilevel contexts that influence COVID-19 vaccine uptake, barriers to vaccination, and vaccine hesitancy among predominantly racialized sexual and gender minority individuals. Semi-structured online interviews explored perspectives and experiences around COVID-19 vaccination. Interviews were recorded, transcribed, uploaded into ATLAS.ti, and reviewed using thematic analysis. Among 40 participants (mean age, 29.0 years [SD, 9.6]), all identified as sexual and/or gender minority, 82.5% of whom were racialized. COVID-19 vaccination experiences were dominated by structural barriers: systemic racism, transphobia and homophobia in healthcare and government/public health institutions; limited availability of vaccination/appointments in vulnerable neighborhoods; absence of culturally-tailored and multi-language information; lack of digital/internet access; and prohibitive indirect costs of vaccination. Vaccine hesitancy reflected in uncertainties about a novel vaccine amid conflicting information and institutional mistrust was integrally linked to structural factors. Findings suggest that the uncritical application of "vaccine hesitancy" to unilaterally explain undervaccination among marginalized populations risks conflating structural and institutional barriers with individual-level psychological factors, in effect placing the onus on those most disenfranchised to overcome societal and institutional processes of marginalization. Rather, disaggregating structural determinants of vaccination availability, access, and institutional stigma and mistrust from individual attitudes and decision-making that reflect vaccine hesitancy, may support 1) evidence-informed interventions to mitigate structural barriers in access to vaccination, and 2) culturally-informed approaches to address decisional ambivalence in the context of structural homophobia, transphobia, and racism.

Exploring the experiences of wellbeing, health, and healthcare among women who have been domestically sex trafficked in Ontario, Canada: A qualitative study protocol

INTRODUCTION

Although there is a growing body of evidence to suggest that persons who have been sex trafficked can suffer devastating health consequences and often face challenges accessing suitable care that addresses their health and overall well-being, little existing research has adopted a survivor-informed approach. Centering the voices of sex-trafficked women in this research will provide valuable insights into their health-related experiences and can help lay the foundation for survivor-centric healthcare responses.

METHODS AND ANALYSIS

Using a semi-structured interview guide, we will interview women who have been domestically sex trafficked in Ontario; recruitment will continue until data saturation is reached. Interview questions and prompts will elicit information about women's experiences prior to, during, and after their trafficking ordeal, with particular attention paid to their encounters with healthcare providers. Intersectionality theory will inform strategies for recruitment, data collection, and data analysis. Data will be analyzed deductively as well as inductively using Braun and Clarke's six phases of reflexive thematic analysis. The study's design was informed by the consolidated criteria for reporting qualitative research (COREQ), which ensures a comprehensive and robust reporting of interview data. We will continue to adhere to the COREQ checklist throughout the data collection, analysis, and findings write-up phases, helping to ensure methodological accuracy and transparency.

DISCUSSION

To our knowledge, this will be the first Canada-specific investigation to apply intersectionality theory to explore the experiences of well-being, health, and healthcare from the perspectives of women who have been domestically sex trafficked. The results of this study hold the potential to improve responses to trafficking within the healthcare sector. Specifically, the findings could be used to inform the development of education materials and curricula for medical students and continuing professional education for health and allied healthcare providers. They could also inform the creation of patient experience surveys and intake forms for sex trafficked patients.

Covid-19 Vaccine Hesitancy and Under-Vaccination among Marginalized Populations in the United States and Canada: A Scoping Review

BACKGROUND

Amid persistent disparities in Covid-19 vaccination and burgeoning research on vaccine hesitancy (VH), we conducted a scoping review to identify multilevel determinants of Covid-19 VH and under-vaccination among marginalized populations in the U.S. and Canada.

METHODS

Using the scoping review methodology developed by the Joanna Briggs Institute, we designed a search string and explored 7 databases to identify peer-reviewed articles published from January 1, 2020-October 25, 2022. We combine frequency analysis and narrative synthesis to describe factors influencing Covid-19 VH and under-vaccination among marginalized populations.

RESULTS

The search captured 11,374 non-duplicated records, scoped to 103 peer-reviewed articles. Among 14 marginalized populations identified, African American/Black, Latinx, LGBTQ+, American Indian/Indigenous, people with disabilities, and justice-involved people were the predominant focus. Thirty-two factors emerged as influencing Covid-19 VH, with structural racism/stigma and institutional mistrust (structural)(n = 71) most prevalent, followed by vaccine safety (vaccine-specific)(n = 62), side effects (vaccine-specific)(n = 50), trust in individual healthcare provider (social/community)(n = 38), and perceived risk of infection (individual)(n = 33). Structural factors predominated across populations, including structural racism/stigma and institutional mistrust, barriers to Covid-19 vaccine access due to limited supply/availability, distance/lack of transportation, no/low paid sick days, low internet/digital technology access, and lack of culturally- and linguistically-appropriate information.

DISCUSSION

We identified multilevel and complex drivers of Covid-19 under-vaccination among marginalized populations. Distinguishing vaccine-specific, individual, and social/community factors that may fuel decisional ambivalence, more appropriately defined as VH, from structural racism/structural stigma and systemic/institutional barriers to vaccination access may better support evidence-informed interventions to promote equity in access to vaccines and informed decision-making among marginalized populations.

A Structural Analysis of Gender-Based Violence and Depression in the Lives of Sexual Minority Women and Trans People

This article explores structural mechanisms that are the context for violence and depression in the lives of sexual minority women and trans people in Ontario, Canada. The article draws on interviews with 14 people who reported experiences of depression in the previous year, foregrounding three representative narratives. Narrative and case study analysis reveal that violence is a repeated and cumulative experience over lifetimes, occurring across different interpersonal contexts and institutional encounters. A common theme across the narratives is that experiences of violence are connected to a broader context in which structural arrangements, cultural norms, and institutional processes create conditions where marginalized people are put in harm's way, perpetrators are empowered, and justice and access to help are elusive. As the violence experienced by these sexual minority women and trans people is rooted in structural and cultural oppression represented in poverty, racism, misogyny, homophobia, and transphobia, the prevention of violence and its consequences for these and other marginalized populations requires systemic transformation of the structures and systems that currently allow and perpetuate harm.

Youth cannabis use in Canada post-legalization: service providers' perceptions, practices, and recommendations

BACKGROUND

In 2018, Canada legalized recreational cannabis use with the purpose of protecting youth and restricting access. However, concerns have been raised that this objective has not been met as rates of cannabis use among youth aged 16-24 have not declined. Youth cannabis use is associated with various adverse effects including psychosis, anxiety, depression, suicidality, respiratory distress, cannabinoid hyperemesis syndrome, and intoxications. Service providers play a crucial role in addressing youth cannabis use. This study aimed to understand Ontario service providers' perceptions, practices, and recommendations on youth cannabis use.

METHODS

This mixed method study included a survey and two focus groups. The survey was distributed to mental health service providers serving youth aged 16-24 across Ontario who were given the option to participate in a focus group. The survey included closed and open-ended questions regarding perceptions, practices, and recommendations, while the focus groups explored these categories in greater depth. Descriptive statistics were used to analyze close-ended questions and interpretative content analysis was applied for open-ended questions. Focus group data were analyzed using thematic analysis.

RESULTS

The survey was completed by 160 service providers and 12 participated in two focus groups. Regarding perceptions, 60% of survey participants agreed with legalization, 26% had a strong understanding of medical versus recreational cannabis, 84% believed that cannabis has physical and mental health risks, and 49% perceived stigmatization. Less than half of the survey participants reported screening or assessing cannabis use, 16% stated they are highly familiar with treating cannabis use, and 67% reported that they rarely work with families. Subthemes identified in the focus groups under perceptions included normalization and stigmatization, harms for youth, and stigma, racism, and discrimination. Subthemes under practice included cannabis not being the primary focus, challenges with screening, assessment, and intervention, and referral to specialized services. Both the survey and focus group participants recommended increasing public education, enhancing service provider training, improving regulation and policies, reducing stigma and minimization, improving service access, and providing more culturally responsive services.

CONCLUSION

Youth cannabis use in Canada remains a significant public health concern, necessitating a more comprehensive plan to protect Ontario youth and reduce associated harms.

Access to mental health and addiction services for youth and their families in Ontario: perspectives of parents, youth, and service providers

BACKGROUND

Canadian youth (aged 16-24) have the highest rates of mental health and addiction concerns across all age groups and the most unmet health care needs. There are many structural barriers that contribute to the unmet mental health care needs of youth including lack of available and appropriate services, high costs, long wait times, fragmented and siloed services, lack of smooth transition between child and adult services, stigma, racism, and discrimination, as well as lack of culturally appropriate treatments. Levesque et al. (2013) developed a framework to better understand health care access and this framework conceptualizes accessibility across five dimensions: (1) approachability, (2) availability, (3) affordability, (4) appropriateness, and (5) acceptability. The purpose of this study was to explore access to addiction and mental health services for youth in Ontario, Canada from the perspectives of youth, parents, and service providers.

METHODS

This qualitative study was a university-community partnership exploring the experiences of youth with mental health concerns and their families from the perspectives of youth, caregivers, and service providers. We conducted semi-structured interviews and used thematic analysis to analyze data.

RESULTS

The study involved 25 participants (n = 11 parents, n = 4 youth, n = 10 service providers). We identified six themes related to structural barriers impacting access to youth mental health and services: (1) "The biggest barrier in accessing mental health support is where to look," (2) "There's always going to be a waitlist," (3) "I have to have money to be healthy," (4) "They weren't really listening to my issues," (5) "Having more of a welcoming and inclusive system," and (6) "Health laws aren't doing what they need to do."

CONCLUSION

Our study identified five structural barriers that map onto the Levesque et al. healthcare access conceptual framework and a sixth structural barrier that is not adequately captured by this model which focuses on policies, procedures, and laws. The findings have implications for policies and service provisions, and underline the urgent need for a mental health strategy that will increase access to care, improve mental health in youth, decrease burden on parents, and reduce inequities in mental health policies and services.

Cannabis use among youth in Canada: a scoping review protocol

INTRODUCTION

Canadian youth (aged 15-24) have the highest rates of cannabis use globally. There are increasing concerns about the adverse effects of cannabis use on youth physical and mental health. However, there are gaps in our understanding of risks and harms to youth. This scoping review will synthesise the literature related to youth cannabis use in Canada. We will examine the relationship between youth cannabis use and physical and mental health, and the relationship with use of other substances. We will also examine prevention strategies for youth cannabis use in Canada and how the literature addresses social determinants of health.

METHODS AND ANALYSIS

Using a scoping review framework developed by Arksey and O'Malley, we will conduct our search in five academic databases: MEDLINE, Embase, APA PsycInfo, CINAHL and Web of Science's Core Collection. We will include articles published between 2000 and 2021, and articles meeting the inclusion criteria will be charted to extract relevant themes and analysed using a qualitative thematic analysis approach.

ETHICS AND DISSEMINATION

This review will provide relevant information about youth cannabis use and generate recommendations and gaps in the literature. Updated research will inform policies, public education strategies and evidence-based programming. Results will be disseminated through an infographic, peer-reviewed publication and presentation at a mental health and addiction conference. Ethics approval is not required for this scoping review.

Evaluating the measurement invariance of the Personality Inventory for DSM-5 (PID-5) in Black Americans and White Americans

The Personality Inventory for the DSM-5 (PID-5) assesses the five pathological personality trait domains that comprise the descriptive core of the DSM-5 Alternative Model of Personality Disorders (AMPD). The PID-5 five-domain factor structure is aligned with the AMPD and is reported as replicable across samples in the U.S., in other countries, and in different languages. In this study, the PID-5 factor structure is examined in two distinct racial groups within the U.S.-White Americans (WA) and Black Americans (BA). Student participants from four universities in the U.S. (N = 1,834)-composed of groups of WA (n = 1,274) and BA (n = 560)-were proportionally parsed into derivation and replication subsamples. The "traditional" PID-5 five-factor structure emerged for the WA group in the derivation subsample and was subsequently confirmed in the WA replication subsample. In the BA group derivation subsample, a single-factor solution emerged, which was also confirmed in the BA replication sample. This single-factor solution in the BA group reflects large shared covariation across all pathological personality domains, suggesting an undifferentiated, broadly based level of demoralization represented by the item pool of the PID-5. We argue that this structure can be construed as mirroring a racialized and prejudice-based living experience for many BAs in a predominantly non-Black society. Based on the results with the samples employed in the present study, we conclude that the PID-5 is not an equivalent measure of pathological personality traits across Black Americans and White Americans. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Recovery-oriented social work practice in mental health and addictions: a scoping review protocol

INTRODUCTION

Social work is a key profession in the field of mental health worldwide and the profession has values that are aligned with a recovery paradigm. However, there are gaps in understanding how social workers are applying the recovery paradigm in practice. This study will scope and synthesise the literature related to recovery and social work practice in mental health and addictions. There will also be an exploration of best practices and gaps in recovery-oriented social work practice.

METHODS AND ANALYSIS

Using a scoping review framework developed by Arksey and O'Malley, we will conduct our search in five academic databases: PsycINFO, Medline, CINAHL Plus, Sociological Abstracts and Social Services Abstracts. Articles meeting inclusion criteria will be charted to extract relevant themes and analysed using a qualitative thematic analysis approach.

ETHICS AND DISSEMINATION

This review will provide relevant information about best practices and gaps in recovery-oriented social work practice in mental health and addictions. The study will inform the development of mental health curricula in social work programmes and clinical settings. Results will be disseminated through a peer-reviewed journal and at conferences focusing on mental health, addictions, and social work education. Ethics approval is not required for this scoping review.

In spite of the system: A qualitatively-driven mixed methods analysis of the mental health services experiences of LGBTQ people living in poverty in Ontario, Canada

Lesbian, gay, bisexual, trans, and/or queer (LGBTQ) people face barriers to accessing mental health care; however, we know little about service experiences of low income LGBTQ people. In this qualitatively-driven mixed methods study, over 700 women and/or trans people completed an internet survey, of whom 12 LGBTQ individuals living in poverty participated in interviews. Low income LGBTQ respondents saw more mental health professionals and had more unmet need for care than all other LGBTQ/income groups. Narrative analysis illustrated the work required to take care of oneself in the context of extreme financial constraints. These findings highlight the mechanisms through which inadequate public sector mental health services can serve to reproduce and sustain both poverty and health inequities.

Depression and discrimination in the lives of women, transgender and gender liminal people in Ontario, Canada

This article uses an intersectionality lens to explore how experiences of race, gender, sexuality, class and their intersections are associated with depression and unmet need for mental healthcare in a population of 704 women and transgender/gender liminal people from Ontario, Canada. A survey collecting demographic information, information about mental health and use of mental healthcare services, and data for the Everyday Discrimination Scale and the PHQ-9 Questionnaire for Depression was completed by 704 people via Internet or pen-and-paper between June 2011 and June 2012. Bivariate and regression analyses were conducted to assess group differences in depression and discrimination experiences, and predictors of depression and unmet need for mental healthcare services. Analyses revealed that race, gender, class and sexuality all corresponded to significant differences in exposure to discrimination, experiences of depression and unmet needs for mental healthcare. Use of interaction terms to model intersecting identities and exclusion contributed to explained variance in both outcome variables. Everyday discrimination was the strongest predictor of both depression and unmet need for mental healthcare. The results suggest lower income and intersections of race with other marginalised identities are associated with more depression and unmet need for mental healthcare; however, discrimination is the factor that contributes the most to those vulnerabilities. Future research can build on intersectionality theory by foregrounding the role of structural inequities and discrimination in promoting poor mental health and barriers to healthcare.

Short communication: Substituting dry distillers grains with solubles and rumen-protected amino acids for soybean meal in late-lactation cows' diets based on corn silage or ryegrass silage

Excess protein in dairy cattle diets increases production costs and contributes to environmental pollution. The objective of the present study was to evaluate the effect of feeding dry distillers grains with solubles (DDGS) supplemented with rumen-protected Lys and Met in place of solvent-extracted soybean meal on the performance of late-lactation cows. Two experiments were carried out, with each using 24 late-lactating dairy cows distributed among 4 pens. In trial 1, corn silage was the main forage source. Control (HP1) total mixed ration (TMR) contained 16.3% crude protein (CP) with soybean meal as the main protein source. Treatment TMR (LP1) had 13.7% CP when soybean meal was replaced with DDGS and rumen-protected Lys and Met. Forage in trial 2 was ryegrass silage; control TMR (HP2; 15.4% CP) contained soybean meal and rumen-protected Met, whereas treatment TMR (LP2; 13.8% CP) contained DDGS and rumen-protected Lys and Met. Trials were analyzed as crossover design using the MIXED procedure of SAS (SAS Institute Inc., Cary NC) with cow as sampling unit and pen as the experimental unit. Treatments were similar in dry matter intake (21.0 and 20.4 kg/cow per day for HP1 and LP1, respectively) and milk yield (20.7 and 20.5 kg/cow per day for HP1 and LP1, respectively) during trial 1. Milk composition was similar between treatments, averaging 4.22, 3.73, 4.54, and 9.15, respectively, for fat, protein, lactose, and solids nonfat. Milk urea nitrogen decreased from 17.2 mg/dL for HP1 to 9.93 mg/dL for LP1. In trial 2, no significant differences were observed for dry matter intake (21.4 and 20.9 kg/cow per day for HP2 and LP2, respectively), milk yield (28.1 and 26.6 kg/d for HP2 and LP2, respectively), fat yield (0.99 vs. 0.92 kg/d for HP2 and LP2, respectively), protein yield (0.94 vs. 0.86 kg/d for HP2 and LP2, respectively) and lactose yield (1.37 vs. 1.28 for HP2 and LP2, respectively). Milk urea nitrogen decreased from 9.88 mg/dL with HP2 to 6.39 mg/dL with the LP2 treatment. Milk N efficiency tended to be higher for LP treatments in trial 1, but not in trial 2. Low milk urea N suggested nitrogen losses to the environment may be lower when cows were fed diets based on DDGS in both trials. The studies indicated that DDGS with rumen-protected Lys and Met could substitute solvent-extracted soybean meal in low-protein corn silage- and ryegrass silage-based diets for late-lactation dairy cows averaging 20.6 or 27.4 kg of milk/d, respectively.

Dynamic tunneling force microscopy for characterizing electronic trap states in non-conductive surfaces

Dynamic tunneling force microscopy (DTFM) is a scanning probe technique for real space mapping and characterization of individual electronic trap states in non-conductive films with atomic scale spatial resolution. The method is based upon the quantum mechanical tunneling of a single electron back and forth between a metallic atomic force microscopy tip and individual trap states in completely non-conducting surface. This single electron shuttling is measured by detecting the electrostatic force induced on the probe tip at the shuttling frequency. In this paper, the physical basis for the DTFM method is unfolded through a physical model and a derivation of the dynamic tunneling signal as a function of several experimental parameters is shown. Experimental data are compared with the theoretical simulations, showing quantitative consistency and verifying the physical model used. The experimental system is described and representative imaging results are shown.

Short communication: Effects of increasing protein and energy in the milk replacer with or without direct-fed microbial supplementation on growth and performance of preweaned Holstein calves

Forty-four Holstein calves were fed a direct-fed microbial (DFM) and 1 of 2 milk replacers to evaluate calf performance and growth. Treatments were (1) a control milk replacer [22:20; 22% crude protein (CP) and 20% fat], (2) an accelerated milk replacer (27:10; 27% CP and 10% fat), (3) the control milk replacer with added DFM (22:20+D), and (4) the accelerated milk replacer with added DFM (27:10+D). Dry matter intake, rectal temperatures, respiration scores and rates, and fecal scores were collected daily. Body weight, hip and withers height, heart girth, blood, and rumen fluid samples were collected weekly. Effects of treatment, sex, week, and their interactions were analyzed. Calves fed an accelerated milk replacer, regardless of DFM supplementation, consumed more CP and metabolizable energy in the milk replacer. No treatment differences were found for starter intake or intake of neutral detergent fiber or acid detergent fiber in the starter. Calves fed the accelerated milk replacer had greater preweaning and weaning body weight compared with calves fed the control milk replacer. Average daily gain was greater during the preweaning period for calves fed the accelerated milk replacer, but the same pattern did not hold true during the postweaning period. Feed efficiency did not differ among treatments. Hip height tended to be and withers height and heart girth were greater at weaning for calves fed the accelerated milk replacer compared with calves fed the control milk replacer. Fecal scores were greatest in calves fed DFM. Overall acetate, propionate, butyrate, and n-valerate concentrations were lower in calves fed the accelerated milk replacer, but DFM did not have an effect. Rumen pH was not different. Blood metabolites were unaffected by DFM supplementation, but calves fed the accelerated milk replacer had increased partial pressure of CO2, bicarbonate, and total bicarbonate in the blood. Direct-fed microbial supplementation did not appear to benefit the calf in this trial.

"Sisters, Mothers, Daughters and Aunties": HIV vaccine acceptability among African, Caribbean and other Black women in Toronto

OBJECTIVES

Black women in Canada are at disproportionately high risk for HIV. We assessed HIV vaccine acceptability and correlates of acceptability among Black women from African and Caribbean communities in Toronto.

METHODS

"Sisters, Daughters, Mothers, and Aunties" was a community-based research project. Black women of African and Caribbean descent were recruited using venue-based sampling across diverse community organizations in Toronto. We used a structured questionnaire to collect data on socio-demographic characteristics and acceptability of 8 future HIV vaccines, each defined by a set of 7 dichotomous attributes. Conjoint analysis was used to quantify the relative impact of vaccine attributes on acceptability, with multiple regression to adjust for socio-demographic characteristics associated with overall acceptability.

RESULTS

Mean vaccine acceptability was 58.8 (SD=17.2) on the 100-point scale. Efficacy had the greatest impact on acceptability, followed by side effects, cost, duration of protection, and number of doses. Acceptability of a high (99%) efficacy vaccine (70.1/100) was significantly greater than for a 50% efficacy vaccine (47.6/100). Vaccine acceptability was significantly higher among women of Caribbean versus African descent, ever married versus single women, and women with full-time versus part-time employment.

CONCLUSIONS

Black women in Toronto indicated a modest level of acceptability for future HIV vaccines. Educational interventions that address the benefits of partially efficacious vaccines and clearly explain potential side effects, as well as vaccine cost subsidies may promote HIV vaccine uptake. Differences in acceptability within Black communities suggest that tailored multi-level interventions may mitigate barriers to uptake.

Stable inhibition of specific estrogen receptor α (ERα) phosphorylation confers increased growth, migration/invasion, and disruption of estradiol signaling in MCF-7 breast cancer cells

Elevated phosphorylation of estrogen receptor α (ERα) at serines 118 (S118) and 167 (S167) is associated with favorable outcome for tamoxifen adjuvant therapy and may serve as surrogate markers for a functional ERα signaling pathway in breast cancer. It is possible that loss of phosphorylation at S118 and/or S167 could disrupt ERα signaling, resulting in aggressive ERα-independent breast cancer cells. To this end, MCF-7 breast cancer cells were stably transfected with an ERα-specific short hairpin RNA that reduced endogenous ERα. The resulting cell line was stably transfected with wild-type ERα (ER-AB cells), or ERα containing serine to alanine mutation at S118 or S167 (S118A cells and S167A cells, respectively). These stable cell lines expressed approximately equivalent ERα compared with parental MCF-7 cells and were evaluated for growth, morphology, migration/invasion, and ERα-regulated gene expression. S118A cells and S167A cells exhibited increased growth and migration/invasion in vitro. Forward- and side-scatter flow cytometry revealed that S167A cells were smaller in size, and both S118A and S167A cells exhibited less cellular complexity. S118A and S167A cells expressed pancytokeratin and membrane localization of β-catenin and did not express vimentin, indicating retention of epithelial lineage markers. Expression of ERα-target genes and other genes regulated by ERα signaling or involved in breast cancer were markedly altered in both S118A and S167A cells. In summary, attenuated phosphorylation of ERα at S118 and S167 significantly affected cellular physiology and behavior in MCF-7 breast cancer cells, resulting in increased growth, migration/invasion, compromised expression of ERα target genes, and markedly altered gene expression patterns.

Professional competencies for promoting recovery in mental illness

This study explored professional caregiving from the perspective of people diagnosed with schizophrenia to develop proposed professional competencies for promoting recovery. We conducted semi-structured qualitative interviews with 40 people diagnosed with schizophrenia to explore their experiences of caregiving. Interview segments related to professional caregiving were analyzed to derive categories and themes that described aspects of caregiving that clients believed contributed to their recovery. The proposed competencies derived from the interviews overlap with hypothesized competencies identified in the literature, but also suggest other areas of skill and attitude that relate to promoting recovery, including use of time, talk, and teamwork. The significance participants attach to time and talk suggests that services play an important role in recovery by creating the space for service users and service providers to engage in recovery-promoting practices.

Electronic characterization of individual monolayer protected Au clusters by single electron tunneling force spectroscopy

Gold monolayer protected clusters (MPCs) exhibit strong quantum confinement effects and size dependent electronic, optical and chemical properties. Chemical tuning of these properties can be achieved by established synthesis methods, providing an excellent system for the study of the relationship between chemical and electronic structure. In this paper, the first electronic spectra of individual Au MPCs (Au(25)) acquired by single electron tunneling force spectroscopy on non-conducting silicon dioxide surfaces are reported. A HOMO-LUMO (highest occupied molecular orbital-lowest unoccupied molecular orbital) energy gap is observed in the Au(25) spectra. Hysteretic charging of the particles is also observed while obtaining the energy spectra. The new single electron tunneling measurement methodology is described. A model explaining the measurements supports the existence of mid-HOMO-LUMO gap defect states.

Influence of calcium and phosphorus feeding on markers of bone metabolism in transition cows

A study was carried out to verify the effect of Ca and P levels on production, digestibility, and serum bone metabolism biomarkers in dairy cows. Fifty-two nonlactating multiparous cows (>or=3 lactations) were confined in a free-stall barn approximately 20 d before calving. A standard close-up diet was fed to cows once daily until d 2 postpartum. Cows were randomly assigned to 1 of 4 dietary treatments arranged in a 2 x 2 factorial approach averaging 0.64% Ca for high Ca (HCa), 0.46% Ca for low Ca (LCa), 0.47% P for high P (HP), and 0.38% P for low P (LP) on a dry matter basis. Experimental diets were fed twice daily from 3 d in milk (DIM) until 31 DIM. Intake and milk yield were recorded daily. Milk samples were collected on d 28, 29, and 30 postpartum for components analyses. Blood samples were drawn 10 d before expected calving, at calving, and at 15 and 30 DIM for serum analyses of osteocalcin, a biomarker of bone accretion, and pyridinoline, a biomarker of bone resorption. Total fecal collection was conducted when cows in a block averaged 20 DIM. Intake and production traits were not significantly affected by any of the dietary treatments. Cows averaged nearly 21 kg/d dry matter intake and 44 kg/d milk yield from 6 to 31 DIM. There were no significant differences across treatments in body weight or body condition score loss. Phosphorus intake, P fecal output, P digestibility, and P apparent absorption were affected by dietary P content. Calcium intake was higher with HCa, but Ca fecal output, digestibility, and apparent absorption showed an interaction between dietary Ca and dietary P. Calcium fecal output was 100.6 g/d for cows fed HCaHP, intermediate for cows on the HCaLP diet (89 g/d), and similar among cows fed the 2 LCa diets (70 g/d with LCaHP and 75 with LCaLP). There was no significant effect of Ca or P on osteocalcin measurements. Pyridinoline concentrations were affected by dietary Ca levels and tended to have a significant dietary Ca x dietary P interaction. Phosphorus apparent digestibility occurred independently of dietary Ca levels. Results of this study suggest that more bone was mobilized in cows fed LCa diets, but excess dietary P caused greater and prolonged bone mobilization regardless of dietary Ca content.

Atomic scale imaging and spectroscopy of individual electron trap states using force detected dynamic tunnelling

We report the first atomic scale imaging and spectroscopic measurements of electron trap states in completely non-conducting surfaces by dynamic tunnelling force microscopy/spectroscopy. Single electrons are dynamically shuttled to/from individual states in thick films of hafnium silicate and silicon dioxide. The new method opens up surfaces that are inaccessible to the scanning tunnelling microscope for imaging and spectroscopy on an atomic scale.

Mothers raising children with sickle cell disease at the intersection of race, gender, and illness stigma

This qualitative study used the long interview method with Canadian mothers of African and Caribbean descent to understand the underresearched experience of raising a child with sickle cell disease (SCD). Mothers' realities were explored through three levels of social organization: daily caregiver coping (micro level); community views of SCD, such as stigma (meso level); and systemic SCD health care provision (macro level). Through the use of population health and structural social work perspectives, mothers' experiences were examined in the context of perceived gender and racial oppression. Saturation was achieved after initial interviews with 10 participants and a four-month postinterview with half of the participants. Mothers commonly reported several daily coping challenges: fear of their children's death, separation anxiety, loss of control over life, helplessness, and loneliness/isolation. SCD stigma interacted with racism, contributed to social isolation, and prevented families from organizing as a group. All mothers perceived racism as a salient factor behind inadequate mainstream SCD health care. Recommendations to improve SCD health care and implications for social work practice and research are discussed. This is the first known Canadian psychosocial study of SCD and investigation into SCD stigma outside of rural Nigeria.

Insight, stigma, and post-diagnosis identities in schizophrenia

This paper examines insight into mental illness, particularly as it applies to people diagnosed with schizophrenia. The paper argues that insight should be reconceptualized as a component of post-diagnosis identities that are defined in relation to other social identities, and under conditions of stigma against mental illness. The proposed conceptualization suggests there are at least four possibilities for post-diagnosis identities in schizophrenia: engulfed, resistant, detached, and empowered. Revising the insight concept to integrate the influence of social context and the potential for multiple post-diagnosis identities could be the basis for therapeutic dialogues with individuals about the implications that diagnosis has for their lives.

Effects of Methionine and Lysine on Fermentation In Vitro and In Vivo, Nutrient Flow to the Intestine, and Milk Production

Three experiments were conducted to investigate the feasibility of using crystalline methionine and lysine as protein supplements for lactating Holstein cows. In the first experiment, Met (dl-methionine) and Lys (l-lysine-HCl) were added to diets used in continuous culture bioreactors to estimate optimal concentrations for use in subsequent in vivo experiments. The second experiment measured ruminal fermentation and nutrient flow to the small intestine when Met and Lys were top-dressed on diets fed to nonlactating cows. The third experiment measured lactation performance when Met and Lys were added to diets fed to late-lactation cows. Providing 0.29 and 2.27% of dry matter as Met and Lys, respectively, provided the largest improvement in fermentation in vitro and these concentrations were used in subsequent experiments. When Met and Lys were top-dressed on diets fed to nonlactating cows, no changes in total tract N digestion were observed. No changes in microbial protein production or ruminal fermentation were observed. Adding Met and Lys did not change production or efficiency of production of milk or milk components by late lactation cows. These data indicate that providing supplemental Met and Lys during late lactation does not significantly improve the protein status of the cow and therefore may not improve milk production.

Care: giving, receiving and meaning in the context of mental illness

Understanding the dynamics of caregiving is essential to providing effective support to individuals and families living with serious mental illnesses. Yet, research in this area has typically explored caregiving without consulting mentally ill people. This paper adds this overlooked viewpoint by exploring the experience of care relationships by people diagnosed with schizophrenia. A secondary analysis of interview data from 21 individuals reveals that relevant dimensions of care relationships include: providers of care; types of care received; self-care; contested practices in care; negotiating practices; recipients of care; and types of care provided to other people. Addressing care within this broader conceptualization can contribute to developing interventions for individuals and families that more fully recognize the potential for people with mental illnesses to be active participants in care relationships.

Ethical considerations in mental health research with racial and ethnic minority communities

Mental health researchers are now expected to include racial and ethnic diversity in their study samples. These studies meet ethics requirements, but the tendency to focus on deontological ethical objectives has not been sufficient to ensure ethical or equitable outcomes for research participants. To ensure these outcomes, we need to emphasize utilitarian ethical principles that take into account the historical and contemporary processes that have promoted negative outcomes for racial and ethnic minority participants in research. Suggestions are made for how both deontological and utilitarian ethical concerns regarding respect, beneficence and justice can be addressed within a broadened research ethic.

Childbirth Experiences of Professional Chinese Canadian Women

OBJECTIVE

To explore the connections between culture and expectations surrounding the childbirth experience for professional Chinese Canadian women.

DESIGN

Descriptive and qualitative, using ethnographic interview.

SETTING

Women were recruited from a community health care center in metropolitan Toronto.

PARTICIPANTS

Six professional Chinese Canadian women who had experienced at least one childbirth.

RESULTS

The respondents described adherence to many traditional values, beliefs, and practices throughout the pregnancy and childbirth experience. However, some practices were modified to address functioning in a context that could not support full expression of cultural traditions. Recent immigration to Canada was associated with less adherence to traditional Chinese rituals and beliefs.

CONCLUSION

Nurses cannot make assumptions about who will use traditional cultural practices or about the circumstances in which they are relevant. Nurses need to be aware of cultural expectations so they can provide culturally competent care, but they should also be aware of how to engage in discussions to clarify individual patient priorities.

Effects of Zinc and Sodium Monensin on Ruminal Degradation of Lysine-HCl and Liquid 2-Hydroxy-4-Methylthiobutanoic Acid,

Four nonlactating, mature, Holstein cows were fitted with ruminal cannula and used in a 4 x 4 Latin square-designed experiment to evaluate the impact of supplemental Zn and monensin on ruminal degradation of Lys and liquid 2-hydroxy-4-methylthiobutanoic acid (HMB). Cows were fed 4.54 kg (as fed) of alfalfa hay top-dressed with 4.54 kg (as fed) concentrate once daily. Concentrates were formulated to provide 0 or 500 mg/kg of Zn as ZnSO4 and 0 or 40 mg/kg of monensin in the total diet. Zinc supplementation provided approximately 22-fold greater dietary Zn than estimated by NRC requirements. On d 14 of each period, cows were dosed via the rumen cannula with 50 g of HMB and 100 g of Lys-HCl, and the concentrations of Lys and HMB were monitored every 0.5 h for 8 h. Supplemental Zn tended to decrease the proportion of acetate in ruminal fluid postfeeding and increased the proportion of propionate in ruminal fluid postfeeding. Supplemental Zn increased mean fluid passage rate from the rumen. Monensin decreased the proportion of acetate and increased the mean proportion of propionate in ruminal fluid, resulting in a decrease in the ratio of acetate to propionate. Monensin also increased the mean fluid passage rate from the rumen. Neither Zn nor monensin affected the apparent rate of ruminal disappearance of HMB or Lys. However, Zn and monensin interacted to alter the ruminal degradability of free Lys but not HMB. These data indicate that Zn and monensin may interact to alter ruminal degradability of free amino acids.

Flow paths of plant tissue residues and digesta through gastrointestinal segments in Spanish goats and methodological considerations1

A sequence of eight twice-daily meals, each marked with different rare earth elements, was fed to 24 Spanish goats (BW = 20.6 +/- 1.94 kg) to produce meal-based profiles of rare earth markers within segments of the gastrointestinal digesta on subsequent slaughter. Accumulative mean residence time and time delay of rare earths and segmental and accumulative mean residence times of indigestible NDF (IDF) were estimated for each sampled segment. Diets consisted of ad libitum access to bermudagrass hay with a limit feeding of one of four supplements: 1) minerals (basal, B); 2) B + energy (E); 3) B + CP (CP); or 4) B + E + CP for 84 d. Mean daily intake (g/kg of BW) during the 5 d before slaughter differed (P < 0.05) via diet for DM but not for IDF (8.0 +/- 0.35 g/kg of BW). Larger estimates of cumulative mean residence time for IDF vs. rare earths were suggested to be the consequence of a meal-induced bias in the single measurement of IDF pool size by anatomical site. The rare earth compartment method was considered more reliable than the IDF pool dilution method because it yielded flow estimates based on the flux of eight meal-dosed rare earth markers over 4 d and was independent of anatomical definitions of pool size. Statistically indistinguishable estimates for gastrointestinal mean residence times for IDF and rare earths conform to assumed indelibility for the specifically applied rare earths and indigestibility of IDF. The potentially digestible NDF (PDF):IDF ratio of dietary fragments (0.8) progressively decreased in the following order: caudodorsal reticulorumen (0.390) > crainodorsal reticulorumen (0.357) approximately reticulum (0.354) > mid-dorsal reticulorumen (0.291) approximately ventral reticulorumen (0.286), to that within the omasal folds and in the abomasum (0.259). Such a gradient of progressively aging mixture of plant tissue fragments is consistent with age-dependent flow paths established in the reticulorumen and flowing to the omasum and abomasum. Such heterogeneity of fragment ages within the reticulorumen is also indicated by the superior fit of marker dose site double dagger marker sampling site model assumptions. Additionally, cyclic meal- and rumination-induced variations in escape rate occur. Estimates of mean escape rates over days, needed for the practice of ruminant nutrition, must consider the complex interactions among plant tissues and the dynamics of their ruminal digestion of PDF.

Thyrotropin releasing hormone interactions with growth hormone secretion in horses

Light horse mares, stallions, and geldings were used to 1) extend our observations on the thyrotropin releasing hormone (TRH) inhibition of GH secretion in response to physiologic stimuli and 2) test the hypothesis that stimulation of endogenous TRH would decrease the normal rate of GH secretion. In Exp. 1 and 2, pretreatment of mares with TRH (10 microg/kg BW) decreased (P < 0.001) the GH response to exercise and aspartate infusion. Time analysis in Exp. 3 indicated that the TRH inhibition lasted at least 60 min but was absent by 120 min. Administration of a single injection of TRH to stallions in Exp. 4 increased (P < 0.001) prolactin concentrations as expected but had no effect (P > 0.10) on GH concentrations. Similarly, 11 hourly injections of TRH administered to geldings in Exp. 5 did not alter (P > 0.10) GH concentrations either during the injections or for the next 14 h. In Exp. 5, it was noted that the prolactin and thyroid-stimulating hormone responses to TRH were great (P < 0.001) for the first injection, but subsequent injections had little to no stimulatory effect. Thus, Exp. 6 was designed to determine whether the inhibitory effect of TRH also waned after multiple injections. Geldings pretreated with five hourly injections of TRH had an exercise-induced GH response identical to that of control geldings, indicating that the inhibitory effect was absent after five TRH injections. Retrospective analysis of pooled, selected data from Exp. 4, 5, and 6 indicated that endogenous GH concentrations were in fact lower (P < 0.01) from 45 to 75 min after TRH injection but not thereafter. In Exp. 7, 6-n-propyl-2-thiouracil was fed to stallions to reduce thyroid activity and hence thyroid hormone feedback, potentially increasing endogenous TRH secretion. Treated stallions had decreased (P < 0.01) concentrations of thyroxine and elevated (P < 0.01) concentrations of thyroid-stimulating hormone by d 52 of feeding, but plasma concentrations of GH and prolactin were unaffected (P > 0.10). In contrast, the GH response to aspartate and the prolactin response to sulpiride were greater (P < 0.05) in treated stallions than in controls. In summary, TRH inhibited exercise- and aspartate-induced GH secretion. The duration of the inhibition was at least 1 h but less than 2 h, and it waned with multiple injections. There is likely a TRH inhibition of endogenous GH episodes as well. Reduced thyroid feedback on the hypothalamic-pituitary axis did not alter basal GH and prolactin secretion.

Re-reading the IPSS research record

The International Pilot Study of Schizophrenia has had a major influence on mental health and research practice since its inception in the 1960s. It is most famous for demonstrating superior outcomes for people living with schizophrenia in developing countries over those living with schizophrenia in developed countries. Like other international research initiatives, it has been shaped by social, political and economic circumstances that contribute to positive and negative outcomes for participating nations. This paper evaluates the contribution of the pilot study by analyzing the discourse surrounding the dissemination of its results. The discussion of long-term outcomes across cultures is used to scrutinize the process of long-term research collaborations across nations. Discourse analysis of the research records indicates that, in various ways, the discourse was constructed to preserve an image of Western superiority and Third World inferiority. As the international research context shifts in psychiatry, it is hoped that inequitable practices that affect this and other studies will be challenged to benefit knowledge-building and mental health care across the world.

Effects of feeding milk replacer once versus twice daily on glucose metabolism in Holstein and Jersey calves

Eighteen Holstein (experiment 1) and 15 Jersey (experiment 2) heifer calves were fed milk replacer once or twice daily to determine effects of feeding frequency on weight gain, starter intake, and glucose metabolism. Body weights were measured weekly from birth to 8 wk. Blood samples were collected at wk 1 through 6 from all calves before and at 30, 60, 90, 120 and 180 min after the morning feeding. Plasma was analyzed for glucose, insulin, glucagon, and nonesterified fatty acids (NEFA). Urine was collected 90 min postfeeding to measure glucose concentration. Treatment did not affect mean starter intake or body weight. In experiments 1 and 2 mean plasma glucagon, glucose, NEFA, and insulin and urinary glucose concentrations were not affected by treatment. There was an interaction of sampling time and treatment for plasma insulin concentrations but not for glucose concentrations in both experiments. Following feeding, calves fed milk replacer once daily had higher insulin concentrations than those fed twice daily. There was an interaction of sampling time and treatment for plasma NEFA concentrations in Jersey calves only. Jersey calves fed milk replacer once daily had higher plasma NEFA concentrations before the morning milk replacer feeding. At wk 3 and 6, frequently sampled intravenous glucose tolerance tests were performed to assess glucose effectiveness, insulin sensitivity, and acute insulin response. In experiments 1 and 2 glucose effectiveness and insulin sensitivity were similar regardless of milk replacer feeding frequency. In Holstein and Jersey calves fed milk replacer twice daily, acute insulin response was greater than in calves fed once daily. However, insulin sensitivity decreased with age, while acute insulin response increased with age. These data suggest that feeding calves milk replacer once daily did not deleteriously affect performance or glucose metabolism regardless of breed.

The social construction of disability in schizophrenia

Chronicity and disability can accompany a diagnosis of schizophrenia, but long-term follow-up studies are demonstrating that these outcomes are not inevitable. There is growing awareness that characteristics of long-term illness previously understood to be part of the disorder can be partially constructed through a convergence of physical, psychological, and social processes. In this study, the potential for social construction of disability was explored through secondary analysis of qualitative data. Findings suggest that family, consumers, professionals, and society each have a role in shaping a person with schizophrenia's perceptions of his or her worth, competence, and place in society but that the individuals are not passive recipients of this input.

Is retrieval-induced forgetting an inhibitory process?

Three experiments investigated memory performance in the retrieval practice paradigm (Anderson, Bjork, & Bjork, 1994; Anderson & Spellman, 1995). This paradigm produces a retrieval-induced forgetting effect, wherein practicing some members of a studied category decreases the recall of other members of that category relative to a baseline. Our findings indicate that the retrieval-induced forgetting effect is replicable but that previous findings supporting an inhibitory account of this phenomenon may not be.

A limit on retrieval-induced forgetting

Retrieving some members of a memory set impairs later recall of semantically related but not unrelated members (M. C. Anderson, R. A. Bjork, & E. L. Bjork, 1994; M. C. Anderson & B. A. Spellman, 1995). The authors investigated whether this retrieval-induced forgetting effect would generalize to testing procedures other than category-cued recall. Although the authors demonstrated a retrieval-induced forgetting effect using a category-cued recall task, they failed to show retrieval-induced forgetting on several different memory tests that used item-specific cues, including a category-plus-stem-cued recall test, a category-plus-fragment-cued recall test, a fragment-cued recall test, and a fragment completion task.

Factors associated with insight among outpatients with serious mental illness

This study examined the relationships between insight, severity of symptoms, diagnosis, locus of control, quality of life, and engulfment among 25 patients with a DSM-III-R diagnosis of schizophrenia and 33 patients with a diagnosis of bipolar disorder. Engulfment is the extent to which a person identifies with the patient role. Severity of symptoms and engulfment were significantly associated with insight. These results are consistent with the notion that poor insight is associated with severe illness. The association between development of deviant or sick roles and awareness of illness warrants further attention.

Effects of dietary protein on whole-body protein turnover and endocrine function in young-adult and aging dogs

Thirty-six adult female Beagles averaging 2 (young-adult) or 8 (geriatric) yr of age were used to assess the effects of graded levels of dietary protein (16, 24, or 32%) on endocrine-controlled regulation of whole-body protein turnover. Rates of whole-body protein synthesis (WBPS) and whole-body protein degradation (WBPD) were estimated using orally administered 15N-glycine and total excreta collection. Although N balance was similar for all dogs, N flux through the metabolic pool increased linearly (P < 0.05) as protein intake increased. Rates of WBPS, WBPD, or the difference between them were not influenced by age (P > 0.10). A quadratic increase (P < 0.05) in WBPS and WBPD was observed in response to dietary protein. Serum insulin-like growth factor-I (IGF-I), IGF-I-binding protein 3, and total IGF-I-binding proteins were higher (P < 0.05) in geriatric dogs than in young-adult dogs regardless of protein intake. These results indicate that dietary protein in excess of 16% may not be required to maintain N balance in young-adult and aging dogs despite the linear increase in N flux through the metabolic pool. Furthermore, age-induced changes in endocrine functionality may differ between dogs and other species.

To see and remember: visually specific information is retained in memory from previously attended objects in natural scenes

What is the nature of the representation formed during the viewing of natural scenes? We tested two competing hypotheses regarding the accumulation of visual information during scene viewing. The first holds that coherent visual representations disintegrate as soon as attention is withdrawn from an object and thus that the visual representation of a scene is exceedingly impoverished. The second holds that visual representations do not necessarily decay upon the withdrawal of attention, but instead can be accumulated in memory from previously attended regions. Target objects in line drawings of natural scenes were changed during a saccadic eye movement away from those objects. Three findings support the second hypothesis. First, changes to the visual form of target objects (token substitution) were successfully detected, as indicated by both explicit and implicit measures, even though the target object was not attended when the change occurred. Second, these detections were often delayed until well after the change. Third, changes to semantically inconsistent target objects were detected better than changes to semantically consistent objects.

Increasing access and building equity into mental health services: an examination of the potential for change

This article explores the use of mental health care services by ethnoracial people in Canada and distinguishes between the reasons for underutilization of services by ethnoracial groups and the barriers which prevent ethnoracial groups from accessing services. Research focusing on Canadian race relations is reviewed to reveal how they are paralleled in the functioning of mainstream mental health care organizations. Existing policies and attitudes are then considered in relation to how they support or impede interventions to increase accessibility to services. Finally, frameworks for organizational change based on multiculturalism and anti-racism are presented, and the advantages and disadvantages of both are articulated.

Predictors of success and satisfaction in the practice of psychiatry: a preliminary follow-up study

BACKGROUND

Few studies have examined the predictors of psychiatrists' perceived success and personal satisfaction with their careers. The present study examines self-reported success and personal satisfaction with their careers in a cohort of psychiatrists followed for more than 20 years.

METHODS

A total of 29 psychiatrists, all of whom had participated in a study during their residency 21 to 24 years earlier, completed a self-report questionnaire. The first set of questions addressed the type and characteristics of their professional practice; the second set assessed aspects of their nonprofessional practice; and the third set assessed aspects of their nonprofessional, personal lifestyles. The personality traits of neuroticism and extraversion were assessed during the residency years and were used as predictors. Composite measures of self-perceived external success and personal satisfaction were computed. Regression models were constructed to determine the best predictors of these composite measures.

RESULTS

Neuroticism proved to be a significant predictor of external success but not of personal satisfaction, with higher scores predicting a lower rating of perceived external success. There were 2 practice characteristics--involvement with research and practising from an orientation other than psychoanalytic--that predicted perception of success. One personal lifestyle characteristic--the perception that one's nonprofessional life sustained professional life--also predicted perception of success. The best predictor of personal satisfaction was overall satisfaction with nonprofessional aspects of life.

CONCLUSIONS

Personality, nonprofessional social support, and engaging in research are associated with greater perceived success and personal satisfaction with a career in psychiatry.

A limit on retrieval-induced forgetting

Retrieving some members of a memory set impairs later recall of semantically related but not unrelated members (M. C. Anderson, R. A. Bjork, & E. L. Bjork, 1994; M. C. Anderson & B. A. Spellman, 1995). The authors investigated whether this retrieval-induced forgetting effect would generalize to testing procedures other than category-cued recall. Although the authors demonstrated a retrieval-induced forgetting effect using a category-cued recall task, they failed to show retrieval-induced forgetting on several different memory tests that used item-specific cues, including a category-plus-stem-cued recall test, a category-plus-fragment-cued recall test, a fragment-cued recall test, and a fragment completion task.

Optical dipole model for photodetection in the near field

Near-field photodetection optical microscopy (NPOM) is a scanning probe technique that has been developed to perform nanometer-scale optical intensity mapping and spectroscopy. In NPOM a nanometer-scale photodiode detector absorbs power directly as it is scanned in the near field of an illuminated sample surface. A model of photodetection in the near and intermediate fields is presented. A brief review of far-field absorption is given for comparison. Far-field absorption measurements measure the imaginary part of the polarizability to first order. In contrast, photodetection in the near field measures the real part of the polarizability. Other aspects of near-field photodetection are also examined, including contrast mechanisms and lateral resolution. NPOM measurements performed on isolated 300-nm spheres show good agreement with the theory.

Dexamethasone increases the expression of membrane macrophage colony stimulating factor from retrovirally transduced tumor cells expressing macrophage colony stimulating factor

Many different tumor cell types (breast, ovarian, glioma, liver and colon) were retrovirally transduced with the human macrophage colony stimulating factor (M-CSF) gene (either the membrane associated form [mM-CSF] or the secreted form [sM-CSF]). These cells were tested for their ability to display increased amounts of mM-CSF in response to dexamethasone. M-CSF-transfected tumor cells expressed additional mM-CSF in response to 18-72 h incubations with 3-15 microg/ml dexamethasone, while non-transfected parental cells were unaffected by this treatment. Increased mM-CSF protein expression on the M-CSF transduced cells was observed by flow cytometry and Western blotting using M-CSF specific antibodies. Northern blot analysis revealed an increase in the mM-CSF specific transcripts within the dexamethasone-treated mM-CSF transduced cells, but this was not seen within the non-transfected tumor cells that were treated with dexamethasone. ICAM-1 expression was unaffected by dexamethasone treatment, indicating that this response is mM-CSF specific. All trans-retinal and 1,25-dihydroxy vitamin D3 compounds that have been reported to induce M-CSF expression failed to increase mM-CSF. When dexamethasone-treated mM-CSF transfected clones were used as target cells for macrophage-mediated cytotoxicity assays, an increased killing with the dexamethasone-treated cells was seen. The macrophage-mediated cytotoxicity of these mM-CSF expressing tumor cells was blocked with excess recombinant M-CSF by saturating M-CSF receptors on the macrophage that is required for this form of tumor cell killing. This work suggests the possibility that dexamethasone may prove useful for vaccination purposes using mM-CSF retrovirally transfected tumor cells.

Membrane macrophage colony-stimulating factor on MADB106 breast cancer cells does not activate cytotoxic macrophages but immunizes rats against breast cancer

Weakly immunogenic, but highly malignant, rat MADB106 breast cancer cells were retrovirally transduced with the membrane form of macrophage colony-stimulating factor (mM-CSF). The cloned mM-CSF-transfected MADB106 cells physically conjugated with macrophages, but were not killed by the macrophages in 48-h cytotoxicity assays. Macrophages killed the mM-CSF-expressing tumors in the presence of noncytotoxic doses of either taxol or taxol plus cisplatin. This indicated that macrophages bind to the mM-CSF expressed on the tumor cells, but for successful macrophage cytotoxicity to occur against mM-CSF-transduced tumor cells other factors must be present. The mM-CSF-transfected tumor cells were rejected when inoculated subcutaneously into normal rats. Cloned MADB106 tumor cells which expressed high amount of mM-CSF were rejected, while tumor cells that displayed lower levels of mM-CSF grew in 60% of the inoculated rats. The mM-CSF-transfected tumors that grew were smaller and had a greater amount of necrosis, compared to the viral vector tumors. Rats that spontaneously rejected the mM-CSF-transfected MADB106 cells showed rechallenge resistance to unmodified parental MADB106 and R3230Ac breast cancers, but not to the F98 glioma. These observations suggest that breast cancer-specific immunity was induced by the inoculation of mM-CSF-expressing MADB106 tumor cells.

Utilization of umbilical cords to assess in utero exposure to persistent pesticides and polychlorinated biphenyls

In support of a study to relate developmental and cognitive effects with prenatal exposure to selected environmental toxicants, we developed and applied an analytical method to determine the concentration of two persistent pesticides, hexachlorobenzene (HCB) and p,p'-dichlorodiphenyldichloroethylene (DDE), and 32 specific polychlorinated biphenyl (PCB) congeners in 316 umbilical cords taken in 1986-1987 from women of the Faroe Islands. The analytical method consisted of homogenization of the cords, partitioning, microsilica gel column chromatography for clean-up, and dual-column capillary gas chromatography (DB-5 and DB-1701) with electron capture detection. Several quality control parameters were followed to monitor the performance of the method. Important criteria used before reporting unknown data were the recovery of in vitro-spiked analytes from a bovine umbilical cord (BUC) and the percentage lipid obtained for a Certified Reference Material (CRM)-350 of mackerel oil (MO). Recoveries of analytes that had been spiked at two concentration ranges (0.26-0.95 ng/g whole weight; 0.35-2.42 ng/g whole weight) into bovine cords ranged from 38.5% to 158% and from 50.4% to 145%, respectively, with a median recovery of 77.7%. Measurement of the percentage lipid for CRM-350 ranged from 73.8% to 107% with a median lipid value of 96.0%. The most prevalent analytes detected (%) in unknown umbilical cords were HCB (100), DDE (100), Ballschmiter/Zell PCBs 153 (100), 138 (98), 180 (98), 170 (93), 118 (88), 187 (86), and 146 (83), with corresponding median concentrations (ng/g whole weight) of 0.17, 1.19, 0.38, 0.30, 0.17, 0.11, 0.12, 0.09, and 0.07, respectively. Total PCB--sum of all measurable PCB congeners--had a median concentration of 1.37 ng/g whole weight. The analytes, which were very low in lipid content were also quantified on a lipid-adjusted basis, which provided an analytical challenge in these umbilical cord samples. The gravimetrically measured lipids in the human specimens ranged from 0.01% to 1.43% (median of 0.18%). In the pooled BUCs, our lipid measurements varied from 0.05% to 0.33% with a median value of 0.13%. The utility of using the umbilical cord as a matrix to assess in utero exposure to persistent environmental pollutants, compared with the use of umbilical cord blood or mother's blood, is worthy of debate.