Prevalence and Predictors of Medical Mistrust Among African Americans with Serious Mental Illness Receiving Care in an Urban Setting

Patients with serious mental illness are reported to have a 10-25 year reduction in life expectancy. Medical mistrust may influence their willingness to seek care (Bynum, S. A., Davis, J. L., Green, B. L., & Katz, R. V. (2012). Unwillingness to participate in colorectal cancer screening: Examining fears, attitudes, and medical mistrust in an ethnically diverse sample of adults 50 years and older. American Journal of Health Promotion : Ajhp, 26(5), 295-300. https://doi.org/10.4278/ajhp.110113-QUAN-20 ). This cross-sectional study used baseline data from a SAMHSA funded demonstration project to describe the prevalence and of medical mistrust among a sample of African American adults with serious mental illness. Medical mistrust was identified using the Medical Mistrust Scale. One hundred and fifty-four participants completed the medical mistrust scale. Approximately, a third (34.4%) reported medical mistrust. After adjusting for financial stability, those endorsing medical mistrust reported nearly 3 times the odds of lacking support (AOR [95% CI]: 2.84 [1.01-7.97]) compared to those not endorsing medical mistrust. The study is among the first to describe elevated rates of medical mistrust among a sample of African Americans people with serious mental illness. An association between medical mistrust and lack of social support was demonstrated.

Optimizing behavioral and pharmacological smoking cessation interventions among people with HIV

BACKGROUND

People with HIV/AIDS (PWH) smoke at nearly three times the rate of the general population. Interventions to promote sustained quitting among PWH are urgently needed.

METHODS

Our study used a randomized factorial design to evaluate the effects of varenicline, compared with placebo, and behavioral cessation therapy, positively smoke free (PSF), compared with standard of care (SOC) among PWH who smoke. The study was designed with power to detect a small effect (Cohen's h of 0.28-0.36) with 240 participants. The primary outcome was the 7-day point prevalence abstinence (PPA) confirmed by exhaled carbon monoxide (ECO) less than 10 ppm for both main effects at 36 weeks. The study was conducted from June 2016 to November 2020. During the study's last year, recruitment was halted because of COVID-19.

RESULTS

The study randomized 184 participants with power to detect a medium effect (Cohen's h of 0.41). Participants were mostly African American (89.7%), men (62.8%) who smoked mentholated cigarettes (96.7%). Nearly all received antiretroviral medication (96.2%). Quit rates for the entire sample were 7.5% at 36 weeks. Compared with those who received placebo, neither those who received varenicline [36 weeks; OR (95% CI), 1.31 (0.33-5.22), P  = 0.70] nor PSF [36 weeks; OR (95% CI), 0.26 (0.03-2.44), P  = 0.24) were more likely to quit smoking.

CONCLUSION

Among an urban living, primarily African American sample of PWH who smoke neither varenicline nor PSF was found to be efficacious at 36 weeks. Our study was not powered to detect small effects sizes. Larger trials are needed to establish tobacco treatment standards for PWH who smoke.

Impact of a Targeted Intervention on Hepatitis C Care Among African Americans With Serious Mental Illness

OBJECTIVE

This study aimed to update findings on the continuum of care for hepatitis C virus (HCV) infection with follow-up data for individuals with serious mental illness and to identify predictors of decisions to decline vaccination.

METHODS

The screening, testing, immunization, risk reduction, and referral (STIRR) intervention has been shown to increase testing and immunization rates. Prevalence of HCV diagnoses, HCV continuum of care, and hepatitis A (HAV) and B (HBV) vaccination were evaluated with laboratory results and chart review.

RESULTS

The prevalence of HCV was 15% (N=40 of 270 African Americans receiving the STIRR intervention). Of the 40 individuals identified as having HCV, 75% (N=30) accepted referral to treatment, of whom 47% (N=14) achieved sustained virologic response. Nearly 68% (N=155) of those eligible received at least partial HAV/HBV vaccination.

CONCLUSIONS

The STIRR intervention facilitated access to treatment for HCV and high acceptance of hepatitis vaccination. Avoidance proved to be a significant factor in decisions to decline vaccination.

Cigarette Smoking Behaviors and Beliefs in Persons Living With HIV in Nairobi, Kenya

Introduction

Persons living with HIV (PLWH) use tobacco at higher rates than the general population in both high-income countries and low- and middle-income countries. Tobacco use rates are increasing in sub-Saharan Africa, the home to most of the world’s PLWH. As the reach of antiretroviral therapy (ART) expands and HIV-related morbidity and mortality wanes, tobacco use is emerging as a leading cause of disease and death in PLWH. A better understanding of tobacco use behaviors in various settings will be crucial to designing optimal tobacco control strategies.

Methods

In late 2019, we enrolled 50 PLWH cigarette smokers from 6 clinical sites in Nairobi, Kenya (4 HIV care clinics and 2 methadone maintenance programs) for one-on-one interviews focusing on their behaviors and beliefs related to tobacco use.

Results

Fifty PLWH smokers completed the interviews. The mean age was 38.5 ± 9.7 years (range 20-57 years) and 68% were male. All were currently receiving ART. They smoked a mean of 14.9 ± 12.4 cigarettes per day, and 82% reported smoking every day. Only 6% reported dual use of smokeless tobacco products. Nicotine dependence was moderate or high in 74%. More than a third (36%) reported a prior history of tuberculosis. In our sample, use of other substances was common, especially alcohol, marijuana, and methadone. On the motivation to quit scale, 90% were at least in the contemplation stage, but only 2% had ever received behavioral cessation counseling, and only 8% had ever used pharmacotherapy (exclusively nicotine replacement therapy). Participants reported significant concern about developing smoking-related illness, exposing others to secondary smoke, and the financial burden associated with their tobacco use. Measures of intrinsic and extrinsic motivation to quit, smoker and abstainer self-concept, and social support yielded encouraging results regarding the possibility of successful quitting.

Conclusions

Tobacco use is an important health concern in PLWH in Kenya. A more thorough understanding of their tobacco use behaviors and beliefs will provide critical information for providers, public health officials, and policy makers as they redouble their efforts to confront this urgent health challenge.

Evolution of service metrics and utilisation of objective discharge criteria in anterior cruciate ligament reconstruction rehabilitation: a retrospective cohort study with historical control in a public hospital physiotherapy department

Background

ACL reconstruction (ACLR) is a common procedure requiring rehabilitation in public hospital physiotherapy departments. The rate of re-rupture and reduced rates of return to sport following ACLR are concerning. Current guidelines recommend a progressive approach to rehabilitation based on objective criteria. The aim of this study was to determine whether a new public hospital model of care incorporating a phase-based program increased physiotherapist utilisation of objective outcome measures, improved service metrics including attendance and rehabilitation completion rates, and increased patient-reported activity and knee function.

Methods

Records from patients attending outpatient physiotherapy after ACL reconstruction (N = 132) were included in a retrospective chart review to assess utilisation of objective measures such as quadricep and hamstring strength assessment, patient attendance and rehabilitation completion. Phone followup (minimum 1 year) was conducted to retrieve patient-reported measures of knee function (IKDC) and activity (Tegner Activity Scale). Patients were categorised by rehabilitation model of care (contemporary - time based [N = 93] vs new - phase based [N = 39]) and logistic regression used to assess the influence of patient factors and model of care on outcomes.

Results

Compliance was equivalent between models of care and completion rates (formal discharge by therapist) were low (30–38%). The probability of a patient receiving objective strength assessment was associated with model of care, sex, BMI and number of sessions attended. The probability of a patient being recorded as discharged from the program was significantly associated with model of care, and duration and number of sessions.

Conclusion

Introduction of an updated model of care including a phase-based rehabilitation program increased physiotherapist utilisation of objective outcome measures in line with current ACLR rehabilitation recommendations, increased total rehabilitation duration and increased total number of sessions attended. Despite this, rehabilitation completion rates remained low, and self-reported activity and knee function remained equivalent.

Level of evidence

III, retrospective cohort study.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40945-020-00093-9.

Perceptions of Problem Gambling Among Methadone Maintenance Treatment Clients and Counsellors

Problem gambling is highly prevalent and rarely treated among clients who attend methadone maintenance treatment programs (MMTPs). Compared with those of the general population, rates of gambling disorder have been found to be elevated among individuals receiving methadone maintenance treatment. Our study aims were to (a) develop a clearer understanding of the gambling experience of clients and counsellors at a methadone clinic and (b) gain insight into the current treatment options and obstacles to treatment in the clinic. Semi-structured interviews focusing on gambling issues were conducted with 8 clients and 8 counsellors at an MMTP located in an urban area. Participants were asked questions to gain an understanding about their perspectives on, treatment options for, and treatment barriers to problem gambling in the clinic. Data were coded by 4 investigators by using a constant comparison, open coding approach. The findings revealed important differences between clients and counsellors: Opinions differed on the definition of problem gambling, obstacles to treatment, and optimal treatment settings. Clients and counsellors also agreed on some elements, including the negative impact that problem gambling can have on recovery from substance use. This examination of responses of counsellors and client feedback provides a useful mechanism to better understand problem gambling in MMTPs.  In addition, the findings have important clinical implications, including a need for more effective screening and treatment in MMTPs and to provide substance use counsellors with training related to problem gambling.RésuméLe jeu compulsif est hautement répandu et rarement traité parmi les clients qui suivent un programme de traitement d’entretien à la méthadone. Comparés à ceux de la population en général, les taux de jeu pathologique ont jugé élevés chez les personnes qui suivent un tel traitement. Les objectifs de notre étude étaient de deux ordres : a) mieux comprendre l’expérience de jeu des clients et les connaissances en cette matière des conseillers d’une clinique de traitement à la méthadone, et b) avoir une meilleure compréhension des options de traitement actuelles et des obstacles au traitement en clinique. Des entretiens semi-structurés portant sur les problèmes de jeu ont été menés auprès de 8 clients et de 8 conseillers dans un centre de traitement, situé en zone urbaine. On a posé des questions aux participants pour mieux comprendre leurs points de vue sur les options et les obstacles au traitement contre le jeu problématique à la clinique. Les données ont été codées par quatre chercheurs en utilisant une approche de codification ouverte à comparaison constante. Les résultats ont révélé des différences importantes entre les clients et les conseillers : les opinions divergeaient quant à la définition du jeu problématique, les obstacles au traitement et les paramètres de traitement optimaux. Les clients et les conseillers ont par ailleurs été d’accord sur certains éléments, notamment l’impact négatif que le jeu problématique peut avoir sur le rétablissement d’une consommation abusive. L’examen des réponses des conseillers et des commentaires des clients constitue un mécanisme efficace pour mieux comprendre le jeu problématique dans les programmes de traitement d’entretien à la méthadone. De plus, les résultats ont d’importantes répercussions cliniques, notamment la nécessité d’un dépistage et d’un traitement d’entretien à la méthadone plus efficaces et d’une formation sur le jeu problématique pour les conseillers en toxicomanie. 

"Why Me?" Understanding the HCV Care Continuum Among People With Serious Mental Illness

OBJECTIVE

Despite possible cure rates of >90% with new treatment, people with serious mental illness are rarely screened for hepatitis C virus (HCV). A colocated approach may help patients navigate the care continuum.

METHODS

This study used a mixed-methods approach to increase understanding of the HCV care continuum for people with mental illness (N=170). Quantitative data included laboratory testing, risk assessments, and chart reviews. Qualitative interviews (N=9) were conducted to gain a broader understanding.

RESULTS

Thirty-one (18%) patients tested positive for HCV; 13 were cured of HCV, and 10 are still receiving treatment. Qualitative interviews revealed that fear of the diagnosis may be an important treatment barrier.

CONCLUSIONS

Those with serious mental illness who were diagnosed as having HCV and received the colocated prevention and treatment program were able to navigate the continuum of care for HCV treatment. Fear of diagnosis may be an important consideration for future efforts.

Prevalence and potential predictors of gambling disorder among people living with HIV

Specific subsets of the adult population are at an increased risk of problem gambling behaviors. Previous research among these subsets has found increased rates of disordered gambling among those with drug use, alcohol use, mood, anxiety, and personality disorders. To what extent this may apply to the HIV population, known to have a high burden of co-occurring substance use and mental disorders, is not known The current study also examined the effectiveness of The Brief Biosocial Gambling Screen (BBGS) for the diagnosis of gambling disorder. This study examined the prevalence of gambling behaviors and disordered gambling in patients enrolled in an urban HIV clinic. 100 people living with HIV (PLWH) were assessed on gambling behaviors, impulsivity, and criterion on disordered gambling. Screening for gambling disorder using the BBGS was compared to the American Psychiatric Association DSM-5 criterion. The mean age was 53, 44% were female, 60% completed high school or above, and 80% self-identified as unemployed/disabled. 13% met four or more criteria for gambling disorder according to DSM-5 criteria. Participants that met criteria were more likely to report marijuana (p = .044) and heroin (p = .002) use, and greater impulsivity (p < 0.00001) when compared to participants who did not meet criteria. The BBGS was able to effectively screen individuals for disordered gambling with a sensitivity of 100%, specificity of 90.8%, positive predictive value of 56.2%, and a negative predictive value of 100%. These results suggest that urban HIV clinics may need to consider actively screening for gambling disorders, and referring to appropriate counseling and treatment for those who screen positive.

Pilot feasibility study of Heart2HAART: a smartphone application to assist with adherence among substance users living with HIV

BACKGROUND

Smartphones with programmable apps may offer innovative interactive interventions for improving adherence among people living with HIV with substance use problems.

METHODS

This pilot randomized controlled trial sought to primarily determine the usability and feasibility of using a smartphone-based intervention called Heart2HAART as an adjunct to directly observed treatment with adherence counseling compared to directly observed treatment with adherence counseling alone among those with HIV and a history of substance use over a three-month time frame. Participants in the Heart2HAART condition completed an additional survey on usability and acceptability. Adherence was measured using unannounced pill counts assessed via a phone call.

RESULTS

Twenty-eight participants were randomized to receive Heart2HAART (n = 19) or control (n = 9). All were receiving either weekly (n = 9) or daily (n = 19) observed treatment. Among those randomized to Heart2HAART, 63.2% reported no difficulty using the Heart2HAART smartphone application and 94.7% responded that the medication reminders did not interfere negatively with their activities. On average participants used Heart2HAART application 56.8 times over the three-month trial. In analyses adjusting for age, there was no difference in adherence to HAART medication between the Heart2HAART and control group as evaluated by the random pill count assessment (P = .29).

CONCLUSIONS

Heart2HAART was feasible to use during a three-month pilot trial. Future studies may evaluate a more tailored approach, with more robust contingency management.

Impact of a Casino Opening on Gambling Behaviors of People Engaged in Methadone Maintenance

This study examined gambling behavior in the context of a newly opening casino, comparing disordered gamblers to non-disordered gamblers, in a population of individuals involved in methadone maintenance treatment. Disordered gamblers (N = 50) and non-disordered gamblers (N = 50) were surveyed before and after the opening of a new casino on gambling behaviors, substance use, and psychological symptoms. No statistically significant changes in gambling behaviors were observed for disordered gamblers or non-disordered gamblers across time points; however, non-disordered gamblers demonstrated non-significant increases in horse and dog race betting, electronic games, and casino table games. As expected, disordered gamblers were found to spend significantly more money on electronic games and casino table games (p < 0.05) and demonstrated higher rates of drug use and impulsivity than non-disordered gamblers. The introduction of a new casino did not appear to have a major impact on gambling behaviors of individuals attending methadone maintenance treatment, though the non-significant increases in gambling among non-disordered gamblers may indicate that this population is preferentially impacted by the opening of a new casino. Future investigation into the longer term effects of opening a new casino on this population may be warranted.

Outcomes of a brief program, REORDER, to promote consumer recovery and family involvement in care

OBJECTIVE

The Recovery-Oriented Decisions for Relatives' Support (REORDER) intervention is an innovative, manualized protocol utilizing shared decision-making principles with persons who have serious mental illnesses to promote recovery and encourage consideration of family involvement in care. This study compared REORDER to enhanced treatment as usual in a randomized design.

METHODS

Participants included 226 veterans with serious mental illness whose relatives had low rates of contact with treatment staff. REORDER involved up to three consumer sessions followed by up to three relative educational sessions if the consumer and relative consented. Individuals were assessed at baseline and six months later.

RESULTS

Eighty-five percent of the 111 randomly assigned REORDER participants attended at least one REORDER consumer session; of those, 59% had at least one family session. REORDER participants had significantly reduced paranoid ideation and increased recovery at follow-up.

CONCLUSIONS

Participation in REORDER led to marked increases in family participation and improved consumer outcomes.

Telephone based cognitive behavioral therapy targeting major depression among urban dwelling, low income people living with HIV/AIDS: results of a randomized controlled trial

This pilot randomized controlled trial evaluated a previously developed manualized telephone based cognitive behavioral therapy (T-CBT) intervention compared to face-to-face (f2f) therapy among low-income, urban dwelling HIV infected depressed individuals. The primary outcome was the reduction of depressive symptoms as measured by the Hamliton rating scale for depression scale. The secondary outcome was adherence to HAART as measured by random telephone based pill counts. Outcome measures were collected by trained research assistants masked to treatment allocation. Analysis was based on intention-to-treat. Thirty-four participants met eligibility criteria and were randomly assigned to receive T-CBT (n = 16) or f2f (n = 18). There was no statistically significant difference in depression treatment outcomes comparing f2f to T-CBT. Within group evaluation demonstrated that both the T-CBT and the f2f psychotherapy groups resulted in significant reductions in depressive symptoms. Those who received the T-CBT were significantly more likely to maintain their adherence to antiretroviral medication compared to the f2f treatment. None of the participants discontinued treatment due to adverse events. T-CBT can be delivered to low-income, urban dwelling HIV infected depressed individuals resulting in significant reductions in depression symptoms and improved adherence to antiretroviral medication.

TRIAL REGISTRY

Clinical Trial.gov identifier: NCT01055158.

A comparison of adherence to hypoglycemic medications between Type 2 diabetes patients with and without serious mental illness

Inadequate self-management of chronic medical conditions like Type 2 diabetes may play a role in the poor health status of individuals with serious mental illnesses. We compared adherence to hypoglycemic medications and blood glucose control between 44 diabetes patients with a serious mental illness and 30 patients without a psychiatric illness. The two groups did not differ in their ability to manage a complex medication regimen as assessed by a performance-based measure of medication management capacity. However, significantly fewer patients with a mental illness self-reported nonadherence to their hypoglycemic regimens compared to those without a mental illness. Although individuals with mental illnesses also had better control of blood glucose, this metabolic parameter was not correlated with adherence to hypoglycemic medications in either patient group. The experience of managing a chronic mental illness may confer advantages to individuals with serious mental illnesses in the self-care of co-occurring medical conditions like Type 2 diabetes.

Assessing the STIRR model of best practices for blood-borne infections of clients with severe mental illness

OBJECTIVES

People with co-occurring severe mental illness and a substance use disorder are at markedly elevated risk of infection from HIV, hepatitis B virus (HBV), and hepatitis C virus (HCV), but they generally do not receive basic recommended screening or preventive and treatment services. Barriers to services include lack of programs offered by mental health providers and client refusal of available services. Clients from racial-ethnic minority groups are even less likely to accept recommended services. The intervention tested was designed to facilitate integrated infectious disease programming in mental health settings and to increase acceptance of such services among clients.

METHODS

A randomized controlled trial (N=236) compared enhanced treatment as usual (control) with a brief intervention to deliver best-practice services for blood-borne diseases in an urban sample of clients with co-occurring disorders who were largely from racial-ethnic minority groups. The "STIRR" intervention included Screening for HIV and HCV risk factors, Testing for HIV and hepatitis, Immunization against hepatitis A and B, Risk reduction counseling, and medical treatment Referral and support at the site of mental health care.

RESULTS

Clients randomly assigned to the STIRR intervention had high levels (over 80%) of participation and acceptance of core services. They were more likely to be tested for HBV and HCV, to be immunized against hepatitis A virus and HBV, and to increase their knowledge about hepatitis and reduce their substance abuse. However, they showed no reduction in risk behavior, were no more likely to be referred to care, and showed no increase in HIV knowledge. Intervention costs were $541 per client (including $234 for blood tests).

CONCLUSIONS

STIRR appears to be efficacious in providing a basic, best-practice package of interventions for clients with co-occurring disorders.

Assessing the STIRR model of best practices for blood-borne infections of clients with severe mental illness

OBJECTIVES

People with co-occurring severe mental illness and a substance use disorder are at markedly elevated risk of infection from HIV, hepatitis B virus (HBV), and hepatitis C virus (HCV), but they generally do not receive basic recommended screening or preventive and treatment services. Barriers to services include lack of programs offered by mental health providers and client refusal of available services. Clients from racial-ethnic minority groups are even less likely to accept recommended services. The intervention tested was designed to facilitate integrated infectious disease programming in mental health settings and to increase acceptance of such services among clients.

METHODS

A randomized controlled trial (N=236) compared enhanced treatment as usual (control) with a brief intervention to deliver best-practice services for blood-borne diseases in an urban sample of clients with co-occurring disorders who were largely from racial-ethnic minority groups. The "STIRR" intervention included Screening for HIV and HCV risk factors, Testing for HIV and hepatitis, Immunization against hepatitis A and B, Risk reduction counseling, and medical treatment Referral and support at the site of mental health care.

RESULTS

Clients randomly assigned to the STIRR intervention had high levels (over 80%) of participation and acceptance of core services. They were more likely to be tested for HBV and HCV, to be immunized against hepatitis A virus and HBV, and to increase their knowledge about hepatitis and reduce their substance abuse. However, they showed no reduction in risk behavior, were no more likely to be referred to care, and showed no increase in HIV knowledge. Intervention costs were $541 per client (including $234 for blood tests).

CONCLUSIONS

STIRR appears to be efficacious in providing a basic, best-practice package of interventions for clients with co-occurring disorders.

Media and internet ownership and use among mental health outpatients with serious mental illness

OBJECTIVE

To determine whether people with serious mental illness (SMI) and substance use disorder (SUD) use the Internet to receive health information.

METHODS

One hundred people with SMI were surveyed in community mental health clinics.

RESULTS

Participants with SUD were significantly less likely to use the Internet compared to those who without SUD (.34 [.12-.95] p = .04). Internet users with SUD were significantly more likely to report accessing sites topically related to substance abuse (p = .01).

CONCLUSION

Few participants with SMI and SUD used the Internet. Attention to educating patients about quality health information on the Internet may be warranted.

Is implementation of the 5 A's of smoking cessation at community mental health centers effective for reduction of smoking by patients with serious mental illness?

We tested whether implementing the "5 A's" (Ask, Advise, Assess, Assist, Arrange) at six mental health centers reduces smoking among persons with serious mental illness. One hundred and fifty six patients were evaluated just before initiating the 5 A's and after six and 12 months. A delayed control condition evaluated 148 patients six months before 5 A's implementation, just before and then after six months. Six months of the 5 A's produced no effect. Modest cessation and reduction benefits were noted after 12 months. Implementing the 5 A's at community mental health centers may have modest benefit after twelve months.

Use of the internet and other media for health information among clinic outpatients with serious mental illness

OBJECTIVE

This study examined how people with serious mental illness access and use media to receive health information.

METHODS

One hundred people with serious mental illness were interviewed regarding their media use, with a focus on how they get their health information.

RESULTS

Among these participants, 91% had a television (M+/-SD=5.7+/-4.6 hours per day), and 74% indicated it was a primary health information source. One third of the sample had used the Internet. Of these participants, about half (53%) had gone online for health information. Younger participants and those with more education were significantly more likely to use the Internet. Among Internet nonusers, there was still interest in finding health information online; however, expense, lack of computer skills or knowledge, and difficulties with typing and reading prevented doing so.

CONCLUSIONS

Although this sample used television more often than the Internet as a resource, there appears to be interest among persons with serious mental illness in using the Internet as a source of health information and support.

Use of a critical time intervention to promote continuity of care after psychiatric inpatient hospitalization

OBJECTIVES

This study assessed the effectiveness of a brief three-month critical time intervention (B-CTI) model in improving continuity of psychiatric outpatient care for individuals with serious mental illness who are discharged from inpatient psychiatric treatment facilities.

METHODS

A total of 135 consenting veterans who were diagnosed as having serious mental illness and were discharged from an acute inpatient unit were randomly assigned to receive either B-CTI or usual care. The three-month B-CTI intervention begins before discharge. A B-CTI clinician meets with the patient, assesses needs, and maintains a high level of patient contact after discharge. Participants completed interviews at baseline and three months later. Chart reviews provided data on service utilization in the six months postdischarge.

RESULTS

Compared with the control group, the B-CTI group had significantly fewer days between their hospital discharge and their first outpatient service. B-CTI participants were more likely to have had an outpatient visit and to have had more total mental health and substance abuse visits within 30 and 180 days of discharge. They had greater continuity of care as evidenced by a greater number of two-month blocks with two or more outpatient visits over 180 days. Participants in the B-CTI group reported receiving more help in making and keeping medical and mental health appointments, making family contact and community connections, and receiving information on prescribed medications.

CONCLUSIONS

This study provides evidence that a B-CTI targeted at the point of inpatient discharge can be helpful in promoting postdischarge continuity of care for persons with serious mental illness. The limited association of improved continuity of care with patient outcomes in this brief intervention demands further study.

Pumpkin kernel and garlic as alternative treatments for the control of Haemonchus contortus in sheep

Two alternative remedies for controlling Haemonchus contortus in sheep (pumpkin kernel and garlic) were investigated. The experiment involved 18 4-month-old Merino ram lambs with six lambs per treatment group. The lambs were initially drenched to render them worm free, and then infected with 4000 L3 H. contortus larvae, 2 weeks later. Four weeks after infection, faecal egg counts were performed and lambs were allocated into treatment groups and fed their respective diets (control, pumpkin kernel or garlic) for 2 weeks. The lambs were combined into a single group grazing pasture for the last week of the experiment. Faecal worm egg counts (WEC) were carried out weekly for 3 weeks following allocation to treatment diets. Clinical signs of infection observed included liveweight, body condition score and voluntary feed intake. The pumpkin kernel treatment resulted in a 65.5% decrease in the initial level of WEC, but this increased back to the initial level as soon as animals came off treatment. The garlic resulted in a 64.4% decrease in WEC from the initial level and this increased slightly (to 25.5% of the initial level and 43.5% lower than the control) when the animals came off treatment, suggesting that there was a residual effect of the garlic and/or that the garlic had an effect beyond decreasing the fecundity of the parasites. There was no significant difference (P > 0.05) between treatments in liveweight, body condition score or voluntary feed intake. Throughout the experiment voluntary feed intake and liveweight increased while body condition scores remained stable. We concluded that pumpkin kernel and garlic show potential for parasite control by affecting the fecundity of the parasites. Our results also indicate that with good nutrition lambs can cope with high parasite burdens and still be productive during the early stages of infection.

Cathepsin L-deficient mice exhibit abnormal skin and bone development and show increased resistance to osteoporosis following ovariectomy

The role of cathepsin L in normal physiological processes was assessed using cathepsin L homozygous knockout mice (B6;129-Ctsl(tm1Alpk)). These mice were generated using gene targeting in embryonic stem cells. Null mice fail to express mRNA and protein to cathepsin L. They developed normally and were fertile. The distinct phenotypic change exhibited was a progressive hair loss, culminating in extensive alopecia by 9 months of age. Histological analysis of the skin from homozygous mice revealed diffuse epithelial hyperplasia, hypotrichosis, hair shaft fragmentation and utricle formation. These findings provide evidence that cathepsin L is involved in the regulation of epithelial cell proliferation and differentiation in the skin. In addition, the role of cathepsin L in bone remodelling was evaluated. Using bone histomorphometric measurements, trabecular, but not cortical, bone volume was found to be significantly decreased in the cathepsin L heterozygote and homozygote mice compared to the wild-type mice. Following ovariectomy, it was observed that loss of trabecular bone, the most metabolically active component of bone, occurred to a lesser extent in homozygote, and heterozygote mice, than was seen in wild-type mice. These observations suggest that cathepsin L is likely to have a role in controlling bone turnover during normal development and in pathological states.

Discovery of novel, orally active dual NK1/NK2 antagonists

Exploration of the SAR around selective NK2 antagonists, SR48968 and ZD7944, led to the discovery that naphth-1-amide analogues provide potent dual NK1 and NK2 antagonists. ZD6021 inhibited binding of [3H]-NKA or [3H]-SP to human NK1 and NK2 receptors, with high-affinity (K(i)=0.12 and 0.62nM, respectively). In functional assays ZD6021 had, at 10(-7)M, in human pulmonary artery pK(B)=8.9 and in human bronchus pK(B)=7.3, for NK1 and NK2, respectively. Oral administration of ZD6021 to guinea pigs dose-dependently attenuated ASMSP induced extravasation of plasma proteins, ED(50)=0.5mg/kg, and NK2 mediated bronchoconstriction, ED(50)=13mg/kg.

Paternity in horseshoe crabs when spawning in multiple-male groups

Unpaired or satellite male horseshoe crabs, Limulus polyphemus, are attracted to and often form a group around a pair (a female with an attached male) that is nesting in the high intertidal zone. These males are engaged in sperm competition. We observed nesting pairs and their associated satellites in the wild, collected and reared their eggs and used genetic markers to examine paternity. We found that the unpaired, satellite males are highly successful at fertilizing eggs; two satellites can leave the attached male with few fertilizations. Two satellites together are each as successful as one spawning with a pair. A satellite's location around the female greatly affects his success, and males compete for access to a position over the dorsal canal between the prosoma and opisthosoma of the female and under the front margin of the paired male where they are most likely to fertilize eggs. Although eggs and sperm retain their viability for some time after spawning, nearly all eggs are fertilized by the satellites that are around the nesting pair at the time of egg laying and by the attached male. A number of factors including beach current, female size and male behaviour affect the outcome of sperm competition in this externally fertilizing species. Copyright 2000 The Association for the Study of Animal Behaviour.

Nonpeptide tachykinin receptor antagonists. II. Pharmacological and pharmacokinetic profile of SB-222200, a central nervous system penetrant, potent and selective NK-3 receptor antagonist

The pharmacological and pharmacokinetic profile of SB-222200 [(S)-(-)-N-(alpha-ethylbenzyl)-3-methyl-2-phenylquinoline-4-car boxami de], a human NK-3 receptor (hNK-3R) antagonist, was determined. SB-222200 inhibited (125)I-[MePhe(7)]neurokinin B (NKB) binding to Chinese hamster ovary (CHO) cell membranes stably expressing the hNK-3 receptor (CHO-hNK-3R) with a K(i) = 4.4 nM and antagonized NKB-induced Ca(2+) mobilization in HEK 293 cells stably expressing the hNK-3 receptor (HEK 293-hNK-3R) with an IC(50) = 18.4 nM. SB-222200 was selective for hNK-3 receptors compared with hNK-1 (K(i) > 100,000 nM) and hNK-2 receptors (K(i) = 250 nM). In HEK 293 cells transiently expressing murine NK-3 receptors (HEK 293-mNK-3R), SB-222200 inhibited binding of (125)I-[MePhe(7)]NKB (K(i) = 174 nM) and antagonized NKB (1 nM)-induced calcium mobilization (IC(50) = 265 nM). In mice oral administration of SB-222200 produced dose-dependent inhibition of behavioral responses induced by i.p. or intracerebral ventricular administration of the NK-3 receptor-selective agonist, senktide, with ED(50) values of approximately 5 mg/kg. SB-222200 effectively crossed the blood-brain barrier in the mouse and rat. The inhibitory effect of SB-222200 against senktide-induced behavioral responses in the mouse correlated significantly with brain, but not plasma, concentrations of the compound. Pharmacokinetic evaluation of SB-222200 in rat after oral administration (8 mg/kg) indicated sustained plasma concentrations (C(max) = about 400 ng/ml) and bioavailability of 46%. The preclinical profile of SB-222200, demonstrating high affinity, selectivity, reversibility, oral activity, and central nervous system penetration, suggests that it will be a useful tool compound to define the physiological and pathophysiological roles of NK-3 receptors, in particular in the central nervous system.

Chicken beta-globin 5'HS4 insulators function to reduce variability in transgenic founder mice

Transgenic mice and rats play a vital role in the study of human diseases and the advancement of drug development within the pharmaceutical industry. In this report we describe a method which improves the yield of phenotypically desirable transgenic founder mice resulting from each microinjection session and consequently reduces animal requirements for transgenic production. We have shown that by flanking a tyrosinase minigene with tandem copies of the chicken beta-globin 5'HS4 insulator there is a significant reduction in variability between transgenic lines, with resulting mice exhibiting similar levels of coat pigmentation. Furthermore, the presence of insulators leads to visually identical tissue distribution of pigmentation including skin, fur, eyes, points, and foot pads. The overall impact of insulators is to reduce the number of transgenic founders required in order to identity animals with an appropriate expression level and tissue distribution.

Effects of isolation and culture of turkey primary follicular oocytes on morphology and germinal vesicle integrity

A novel approach to the production of transgenic poultry is to use primary follicular oocytes (PFOs). However, fundamental information regarding the impact of isolation and culture procedures on PFO integrity is lacking. This study describes the isolation and culture of PFOs from mature turkeys and the effects of these procedures on PFO morphology and germinal vesicle (GV) integrity. To isolate PFOs, ovarian cortex was incubated in trypsin-EDTA alone or further incubated in collagenase plus hyaluronidase (CH). About 200 to 500 PFOs, ranging in size from less than 100 microns in diameter to 1,000 microns, were recovered from each ovary. The culture of PFOs less than 100 microns in diameter for 4 h resulted in blebbing of the oolemma followed by extrusion of ooplasm. Primary follicular oocytes 100 to 250 microns in diameter survived culture for 24 h whereas larger PFOs survived for up to 7 d. Those PFOs with intact granulosa cell investments survived longer than those fully or partially denuded of granulosa cells with CH. Co-culture of PFOs (100 to 250 microns in diameter) on a monolayer of granulosa cells derived from mature, yellow-yolk follicles augmented PFO survival rates. The rate of GV breakdown was not influenced by the isolation or culture of the PFO. These data provide the basis for developing procedures for the in vitro maturation and in vitro fertilization of isolated PFOs.

Gross appearance of the turkey blastoderm at oviposition

The blastoderm (fertilized ovum) and unfertilized germinal disc (UGD) of fresh laid eggs and eggs stored prior to incubation exhibit subtle but definable morphological variations. Such variations may lead to difficulty when attempting to determine true flock fertility based on the appearance of the blastoderm/UGD. The objectives of this study were to define and categorize such morphological variations and to determine whether sperm influence the frequency distribution of the different categories. Eleven categories of blastoderms were defined based on the relative density and appearance of the area alba, area pellucida, area opaca, and the periblast. The majority of the blastoderms were included in the first four categories. Unfertilized germinal discs were divided into six categories and were best differentiated from the blastoderms by the presence of vacuoles around its central dense area. They were also discernible from blastoderms based on their overall denser appearance. Differences in the frequency distribution of some of the UGD categories between virgin and inseminated hens may be due to the effect that supernumary sperm may have on the organization of the UGD (no fertilization but supernumary sperm present) or blastoderm (fertilized but failed to develop). It is recommended that before starting true fertility determinations during fresh egg breakouts, one should study the appearance of the UGD from virgin hens and then the blastoderm from inseminated hens. One then will learn to appreciate the subtle differences in shape and density of the blastoderm/UGD structural components.

MHC-disassortative mating preferences reversed by cross-fostering

House mice (Mus musculus domesticus) avoid mating with individuals that are genetically similar at the major histocompatibility complex (MHC). Mice are able recognize MHC-similar individuals through specific odour cues. However, to mate disassortatively for MHC genes, individuals must have a referent, either themselves (self-inspection) or close kin (familial imprinting), with which to compare the MHC identity of potential mates. Although studies on MHC-dependent mating preferences often assume that individuals use self-inspection, laboratory experiments with male mice indicate that they use familial imprinting, i.e. males learn the MHC identity of their family and then avoid mating with females carrying 'familial' MHC alleles. To determine if female mice use familial imprinting, we cross-fostered wild-derived female mouse pups into MHC-dissimilar families, and then tested if this procedure reversed their mating preferences compared with in-fostered controls. Our observations of the female's mating behaviour in seminatural social conditions and the genetic typing of their progeny both indicated that females avoided mating with males carrying MHC genes of their foster family, supporting the familial imprinting hypothesis. We show that MHC-dependent familial imprinting potentially provides a more effective mechanism for avoiding kin matings and reducing inbreeding than self-inspection.

Rad23 links DNA repair to the ubiquitin/proteasome pathway

Rad23 is an evolutionarily conserved protein that is important for nucleotide excision repair. A regulatory role has been proposed for Rad23 because rad23 mutants are sensitive to ultraviolet light but are still capable of incising damaged DNA. Here we show that Rad23 interacts with the 26S proteasome through an amino-terminal ubiquitin-like domain (UbL[R23]). The carboxy terminus of Rad23 binds to the Rad4 DNA repair protein and creates a link between the DNA repair and proteasome pathways. The ultraviolet sensitivity caused by deletion of the UbL(R23) domain may therefore arise from its inability to interact with the proteasome. The fusion proteins glutathione S-transferase (GST)-Rad23 and Rad4-haemagglutinin (HA), and the proteasome subunits Cim3 and Cim5, cofractionate through consecutive chromatography steps. The ubiquitin-like domain of human Rad23 (UbL[HRB]) also interacts with the human proteasome. These results demonstrate that ubiquitin-like domains (UbLs) represent a new class of proteasome-interacting motifs.

Nonpeptide tachykinin receptor antagonists: I. Pharmacological and pharmacokinetic characterization of SB 223412, a novel, potent and selective neurokinin-3 receptor antagonist

The in vitro and in vivo pharmacological profile of SB 223412 [(S)-(-)-N-(alpha-ethylbenzyl)-3-hydroxy-2-phenylquinoline-4-carbo xamide], a novel human NK-3 (hNK-3) receptor antagonist, is described. SB 223412 demonstrated enantioselective affinity for inhibition of [125I][MePhe7]neurokinin B (NKB) binding to membranes of CHO cells expressing the hNK-3 receptor (CHO hNK-3). SB 223412, the (S)-isomer, (Ki = 1.0 nM), has similar affinity as the natural ligand, NKB (Ki = 0.8 nM) and another nonpeptide NK-3 receptor antagonist, SR 142801 (Ki = 1.2 nM). SB 223412 was selective for hNK-3 receptors compared with hNK-1 (>10,000-fold selective) and hNK-2 receptors (>140-fold selective), and selectivity was further demonstrated by its lack of effect, in concentrations up to 1 or 10 microM, in >60 receptor, enzyme and ion channel assays. SB 223412 enantioselectively inhibited the NKB-induced Ca++ mobilization in HEK 293 cells stably expressing the hNK-3 receptor. SB 223412 (10-1,000 nM) produced concentration-dependent rightward shifts in NKB-induced Ca++ mobilization concentration-response curves with a Kb value of 3 nM. In addition, SB 223412 antagonized senktide-induced contraction in the isolated rabbit iris sphincter muscle (Kb = 1.6 nM). In mice, oral administration of SB 223412 produced dose-dependent inhibition of behavioral responses induced by the NK-3 receptor-selective agonist, senktide (ED50 = 12.2 mg/kg). Pharmacokinetic evaluation of SB 223412 in rat and dog indicated low plasma clearance, oral bioavailability and high and sustained plasma concentrations after 4 to 8 mg/kg oral dosages. The preclinical profile of SB 223412 (high affinity, selectivity, reversibility and oral activity) suggests that it will be a useful tool compound to define the physiological and pathophysiological roles of NK-3 receptors.

Serum carotenoid concentrations and their reproducibility in children in Belize

Suggestions that carotenoid-containing foods are beneficial in maintaining health have led to several studies of circulating carotenoid concentrations of adults. Because few data are available for children, we report serum carotenoid concentrations of 493 children in Belize. Carotenoid concentrations were determined as part of a survey of vitamin A status of children, most between 65 and 89 mo of age. Reproducibility was tested by collecting a second blood sample 2 wk after the first collection from a subset of children (n = 23) who consumed their habitual diet with no treatment during the interim. Predominant serum carotenoids were lutein/zeaxanthin and beta-carotene, which accounted for 26% and 24% of median total carotenoids, respectively. The three provitamin A carotenoids, alpha- and beta-carotene and beta-cryptoxanthin, constituted 51% of median total carotenoid concentrations. Partial correlations of each carotenoid with fasting retinol concentration indicated that beta-carotene had the highest correlation. Concordance correlation coefficients (rc) for fasting carotenoid concentrations determined 2 wk apart were > or = 0.89 for lycopene, beta-cryptoxanthin, and alpha- and beta-carotene. The rc for lutein/zeaxanthin and total carotenoids was lower, 0.59 and 0.68, respectively, because of higher lutein/zeaxanthin concentrations at the second sampling than at the first. The reproducibility of the concentrations suggests both that individuals have characteristic profiles and that serum carotenoid concentrations can be measured randomly over > or = 2 wk without significant bias.

Plasma flow and net nutrient flux across gut and liver of cattle fed twice daily

The objectives of this study were 1) to quantify daily patterns of plasma flow and metabolite flux through portal-drained viscera (PDV) and liver in cattle fed twice daily and 2) to identify an interval for blood sampling that would approximate the average daily plasma flow and nutrient flux values. Data are from three experiments in which multicatheterized cattle were fed at or near ad libitum intake twice daily. Five lactating primiparous Holstein cows (506 kg, fed at 0730 and 1930) ate 17.3 kg DM/d as chopped alfalfa hay:corn grain plus supplement (urea and minerals) 50:50 (Exp 1). Five beef steers (474 kg, fed at 0900 and 2100) ate 8.3 kg DM/d as chopped switchgrass hay:corn grain plus supplement 37:63 (Exp 2). Six beef steers (306 kg fed at 0900 and 2100) ate 6.9 kg DM/d as chopped alfalfa hay (Exp 3). Plasma flow (by dilution of para-aminohippurate) was measured hourly for 24 h. Plasma flows (mean +/- SE) through PDV were 1,264 +/- 147, 538 +/- 56, and 499 +/- 26 L/h for Exp. 1, 2, and 3, respectively. Corresponding liver flows were 1,662 +/- 216, 642 +/- 41, and 591 +/- 30 L/h. The within-animal differences from their respective daily means were estimated as a function of time of day using nonparametric smoothing. Across experiments, PDV and liver flows were above the daily mean from 1200 to 1400, were not different from the daily mean from 1600 to 1700, and were below the daily mean from 1930 to 2130. Metabolites measured were ammonia, urea, alpha-amino N, and glucose. In general, metabolite flux was not different from the average daily mean values between 1200 and 1600. Blood sampling over 12 h or one 12-h feeding cycle is sufficient for daily plasma flow and metabolite flux estimation in cattle fed twice daily.

Comparison of methods of assessing vitamin A status in children

OBJECTIVE

A study of children (2-8 years; n = 613) in Belize, Central America, was conducted to determine what proportion of the children might be at risk of vitamin A (vit A) deficiency. The data provide an opportunity to compare results of three methods of assessing vit A status in a population which was not severely malnourished. Serum retinyl ester concentrations were also determined; their relevance to one of the tests, the relative dose response (RDR) test, is discussed.

METHODS

The three methods of assessing vit A status were: RDR test, fasting serum retinol concentration, and conjunctival impression cytology (CIC). Retinol-binding protein (RBP), serum retinyl esters and serum zinc concentrations were also determined.

RESULTS

Inadequate vit A status was indicated for 17% of subjects by the RDR test (14% cutoff), for 24% by fasting serum retinol concentration (< 0.87 mumol/L), and for 49% by "abnormal" CIC score. Retinyl esters constituted 24% of serum retinoids at the time (5 hours after a retinyl palmitate dose) at which the second blood sample is taken for the RDR test. Regression tree analyses (CART) indicated ethnicity was a predictor of RDR score; ethnicity, stunting and age were predictors of fasting serum retinol concentration; ethnicity and stunting were predictors of 0-hour retinyl ester concentration.

CONCLUSION

The three indices of vit A status did not identify the same individuals nor indicate the same percentage of the population to be at risk for vit A deficiency. Increased concentrations of retinyl esters at 5 hours compared to those at 0 hours suggest that insufficient retinol may have been taken up by the liver at 5 hours to release all accumulated retinol-binding protein (RBP) in deficient individuals; prevalence of vit A deficiency might therefore be underestimated by the RDR test. The selection of ethnicity as a predictor of RDR score and of 0-hour retinol and retinyl ester concentrations suggests that factors other than vit A status affect vit A metabolism and may affect the RDR test.

Effects of dietary concentrate level on nutrient absorption, liver metabolism, and urea kinetics of beef steers fed isonitrogenous and isoenergetic diets

Six multicatheterized beef steers (421 +/- 21 kg BW) were used to predict the effect of dietary concentrate level on blood flow and net flux of urea and other metabolites across splanchnic tissues. Diets ranged from 0% (switchgrass hay) to 90% concentrate (10% switchgrass hay, 89% cracked corn, 1% urea). Daily DMI varied from 8.01 to 5.34 kg/d. Nitrogen intake (99 g/d) and calculated ME intake (16.8 Mcal/d) were equal among diets. As dietary concentrate increased from 0 to 90%, liver blood flow decreased from 850 to 795 L/h, portal-drained visceral (PDV) blood flow decreased from 750 to 620 L/h, and mesenteric-drained visceral (MDV) blood flow decreased from 270 to 250 L/h. Liver release of urea N was 94 mmol/h when dietary concentrate was less than 20%, then increased to 146 mmol/h at 55% concentrate. Urinary excretion of urea N was 13 mmol/h or less when dietary concentrate was 20% or less, increased to 53 mmol/h at 55% concentrate, then continued to increase to 76 mmol/h at 90% concentrate. Transfer of urea N to PDV ranged from 71 to 91 mmol/h and transfer to MDV ranged from 0 to 10 mmol/h among diets. As dietary concentrate increased from 27 to 63%, VFA release by PDV decreased, net MDV and splanchnic release of glucose increased, and splanchnic tissues switched from net uptake to net release of L-lactate. Net PDV release or liver removal of ammonia or alpha-amino N and net liver release of glucose were not affected. We conclude that the liver responded to changes in the percentage of dietary concentrate by altering urea production and by altering the role of lactate in intermediary metabolism.

Characterization of the metabolites of the peptidomimetic human immunodeficiency virus type 1 protease inhibitor SK&F 107461 in rats using liquid chromatography/mass spectrometry

The metabolic fate of SK&F 107461 [Cbz-Ala-Ala-Phe psi [CHOHCH2] Gly-Val-Val-OMe], a potent and specific inhibitor of the protease encoded by human immunodeficiency virus type 1, in male Sprague-Dawley rats is described. SK&F 107461 is a hexapeptide analog containing a hydroxyethylene linkage in place of one of the peptide bonds, and in which the amino terminus is blocked with a carbobenzyloxy group and the carboxy terminus is modified to a methyl ester. The major metabolites of SK&F 107461 found in bile and urine after intravenous administration of 3H-labeled compound were characterized by LC/MS using either thermospray or continuous flow/FAB models of ionization. Approximately 80% of the administered radioactivity was recovered in the bile of bile duct-exteriorized rats following an intravenous dose. Radiochromatographic profiling indicated that SK&F 107461 was subject to extensive biotransformation. Structures were determined for three major biliary and five major urinary metabolites. Two of the major circulating plasma metabolites observed after intravenous bolus administration had similar retention times to metabolites that were observed in both bile and urine. A pathway for the biotransformation of SK&F 107461 in the rat is proposed. The parent molecule underwent two primary modes of metabolism. Hydrolysis of the carboxy-terminal ester or hydrolysis of the Ala-Ala peptide bond near the amino terminus were the primary metabolic events. All of the other metabolites characterized can be accounted for by exopeptidase activity subsequent to one or both of these primary events. There were no major metabolites observed resulting from anything other than hydrolysis of the ester or peptide bonds in the parent molecule.

The effects of thiocyanate on the intracellular ion concentrations of branchial epithelial cells of brown trout

Exposure of brown trout (Salmo trutta) in fresh water to 0.15 mmol l-1 external thiocyanate for 1 h resulted in a significant decrease in chlorine concentration in the branchial mitochondria-rich (MR) cells from 37 mmol l-1 to 22 mmol l-1. The intracellular sodium concentration in these cells decreased by a similar amount, whilst the intracellular phosphorus concentration increased significantly. In contrast to the MR cells, 0.15 mmol l-1 external thiocyanate had no effect on the intracellular ion concentrations in the pavement epithelial cells. Thiocyanate is known to inhibit chloride uptake in a number of freshwater animals and therefore these data suggest that it is only the MR cells that are involved in the uptake of Cl- in brown trout.

INTRACELLULAR ION CONCENTRATIONS IN BRANCHIAL EPITHELIAL CELLS OF BROWN TROUT (SALMO TRUTTA L.) DETERMINED BY X-RAY MICROANALYSIS

The intracellular concentrations of sodium, chloride, phosphorus and potassium under normal conditions in pavement epithelial (PE) cells of brown trout (Salmo trutta) gill were 66, 51, 87 and 88 mmol l-1 respectively. The concentrations of these elements under identical conditions in mitochondria-rich (MR) cells were not significantly different, except for that of chlorine, which was lower in MR cells (40 mmol l-1). The concentration of sodium in the PE cells decreased slightly after exposure of the fish to low external [Na+] (25 &micro;mol l-1) for 7 days but increased greatly within 5 min of subsequent exposure to 1 mmol l-1 external Na+. These changes in external [Na+] had no significant effect on MR cells. Exposure of fish to low [Cl-] (25 &micro;mol l-1) had no effect on PE or MR cells, but on exposure to 1 mmol l-1 Cl- the concentrations of chlorine, phosphorus and potassium in both types of cells increased, whilst the intracellular sodium concentration decreased only in MR cells. The PE cells were little affected by exposure of the fish to the carbonic anhydrase inhibitor acetazolamide. In contrast, 0.5 mmol l-1 external acetazolamide caused a significant decrease in intracellular phosphorus, chlorine and potassium concentrations in MR cells. This suggests that the PE cells are the sites of sodium uptake in the gills of the brown trout and that chloride uptake occurs via the MR cells. These results are discussed with respect to the sites and possible mechanisms of ionic exchange in freshwater vertebrates.

Isolated lymphoma of genitourinary tract and adrenals

With the routine use of computed tomographic imaging, intrinsic involvement of the genitourinary tract in newly diagnosed non-Hodgkin's lymphoma is seen in as many as 10 percent of patients. Incidental discovery of an extranodal, extra-lymphatic lesion in the genitourinary tract without clinical or radiographic evidence of disease elsewhere, however, is an uncommon occurrence. The clinical presentation and imaging findings in 4 patients with initial manifestation of lymphoma isolated to the kidney, ureter, bladder, and adrenals, respectively, are presented. These patients had no evidence of lymphoma elsewhere, and imaging studies mimicked the more common neoplasms affecting these organs.

Surprisingly uneven distribution of the T cell receptor V beta repertoire in wild mice

We have examined TCR V beta expression in a collection of wild mice. Many of the mice were homozygous for a large deletion at the V beta locus, and many animals also suppressed expression of several V betas using self superantigens. Expression of V beta 8.2 was unexpectedly suppressed by a self superantigen in some wild mice, which was due to the presence in these animals of a variant V beta 8.2 gene. The amino acid changes in this gene product suggest contact sites between V beta and the superantigen. Although all V betas are expressed within each wild mouse population, individual mice have a limited and variable V beta repertoire. The independent origin of multiple V beta deletions and the presence of polymorphic self superantigens suggest that this variation may be maintained by balancing selection.

Oral immunization with sperm antigens: possible therapy for sperm antibodies?

Young adult male CD-1 mice were given intraperitoneal injections (IP) of saline (controls) and pooled sperm or seminal plasma of two autoimmune infertile men and two nonautoimmune fertile men (n = 40 per treatment). Other mice received only an oral challenge with the same antigens (oral controls; n = 20 per treatment). Three weeks after the booster challenge (day 36), 20 mice in each group were orally immunized with the antigens, whereas the other 20 were not (IP controls). Cytotoxic antibody titers (immunoglobulin M) to human sperm were significantly higher in mice IP immunized with sperm or seminal plasma from autoimmune infertile men or orally immunized with autoimmune men's sperm, in contrast to the controls. Oral challenge with sperm or seminal plasma of autoimmune infertile men after the IP immunization with the same resulted in significantly decreased cytotoxic sperm antibody titers (P less than 0.001 versus oral or IP controls in sperm immunization; P less than 0.001 versus IP controls in seminal plasma immunization). Fertility was unaffected by any mode of immunization. It is concluded that, in mice, sperm and seminal plasma antigens from autoimmune infertile men are more immunogenic than those from nonautoimmune fertile men, and oral challenge with the former after an IP establishment of cytotoxic sperm immunity desensitizes the immune mice. These findings may have practical implications in the diagnosis and immunotherapy of infertile men with cytotoxic sperm antibodies.