Stronger hepatitis C virus-specific CD8+ T-cell responses in HIV coinfection.

Hepatitis C virus (HCV) is a widespread chronic infection that shares routes of transmission with human immunodeficiency virus (HIV). Thus, coinfection with these viruses is a relatively common and growing problem. In general, liver disease develops over years with HIV coinfection, when compared to decades in HCV monoinfection. The role of the immune system in the accelerated pathogenesis of liver disease in HIV/HCV coinfection is not clear. In this study, we compared the frequency, magnitude, breadth and specificity of peripheral blood CD4+ and CD8+ T-cell responses between HCV-monoinfected and HCV/HIV-coinfected individuals and between HIV/HCV-coinfected subgroups distinguished by anti-HCV antibody and HCV RNA status. While HIV coinfection tended to reduce the frequency and breadth of anti-HCV CD8+ T-cell responses in general, responses that were present were substantially stronger than in monoinfection. In all groups, HCV-specific CD4+ T-cell responses were rare and weak, independent of either nadir or concurrent CD4+ T-cell counts of HIV-infected individuals. Subgroup analysis demonstrated restricted breadth of CD8+ HCV-specific T-cell responses and lower B-cell counts in HIV/HCV-coinfected individuals without anti-HCV antibodies. The greatest difference between HIV/HCV-coinfected and HCV-monoinfected groups was substantially stronger HCV-specific CD8+ T-cell responses in the HIV-coinfected group, which may relate to accelerated liver disease in this setting.

L-454,560, a potent and selective PDE4 inhibitor with in vivo efficacy in animal models of asthma and cognition.

Type 4 phosphodiesterases (PDE4) inhibitors are emerging therapeutics in the treatment of a number of chronic disorders including asthma, chronic obstructive pulmonary disease (COPD) and cognitive disorders. This study delineates the preclinical profile of L-454,560, which is a potent, competitive and preferential inhibitor of PDE4A, 4B, and 4D with IC50 values of 1.6, 0.5 and 1.2 nM, respectively. In contrast to the exclusive binding of cilomilast and the preferential binding of roflumilast to the PDE4 holoenzyme state (Mg2+-bound form), L-454,560 binds to both the apo-(Mg2+-free) and holoenzyme states of PDE4. The intrinsic enzyme potency for PDE4 inhibition by L-454,560 also results in an effective blockade of LPS-induced TNFalpha formation in whole blood (IC50 = 161 nM) and is comparable to the human whole blood potency of roflumilast. The cytokine profile of inhibition of L-454,560 is mainly a Th1 profile with significant inhibition of IFNgamma and no detectable inhibition of IL-13 formation up to 1 microM. L-454,560 was also found to be efficacious in two models of airway hyper-reactivity, the ovalbumin (OVA) sensitized and challenged guinea pig and the ascaris sensitized sheep model. Furthermore, L-454560 was also effective in improving performance in the delayed matching to position (DMTP) version of the Morris watermaze, at a dose removed from that associated with potential emesis. Therefore, L-454,560 is a novel PDE4 inhibitor with an overall in vivo efficacy profile at least comparable to roflumilast and clearly superior to cilomilast.

Adherence to immunosuppression: a prospective diary study.

Immunosuppression adherence among kidney transplant recipients is essential for graft survival. However, nonadherence is common, jeopardizing graft survival. Besides skipping dosages, little is known about other forms of medication nonadherence and their underlying reasons. This study sought to examine patients' extent of medication adherence over time and reasons for nonadherence. Thirty-nine new kidney transplant recipients were asked to complete a month-long medication-taking diary that included reporting medication nonadherence such as skipped medications, medications taken early or late, taking dosages greater or less than prescribed, and the reason for each occurrence of nonadherence. Of the 20 (51%) patients who completed the diary, 11 (55%) reported at least 1 form of nonadherence. Eleven patients reported taking their immunosuppression at least 1 hour later than the prescribed time, 1 patient reported skipping medication, but no patients reported changing the dosage on their own. Immunosuppression was taken on average 1.5 hours after the prescribed time. Of those patients who took their medications late, there were on average 3.1 occasions of taking it late. The most common reasons for this behavior included health care-related issues, followed by oversleeping, being away from home, work-related barriers, and forgetting. The majority of kidney transplant recipients took medications later than prescribed during 1 month. Future research should determine the clinical impact on graft function of late administration of immunosuppression. Interventions should be designed to better assist kidney recipients with taking medications on time, especially when they are away from home.

Neutrophil elastase-deficient mice form neutrophil extracellular traps in an experimental model of deep vein thrombosis.

UNLABELLED: ESSENTIALS: Neutrophil elastase (NE) plays a role in extracellular trap formation (NETosis) triggered by microbes. The contribution of NE was evaluated in mouse NETosis models of sterile inflammation and thrombosis. NE is not required for mouse neutrophil NET production in vitro with non-infectious stimuli. NE deficiency had no significant effect on thrombosis in the inferior vena cava stenosis model. BACKGROUND: Neutrophil serine proteases have been implicated in coagulation and neutrophil extracellular trap (NET) formation. In human neutrophils, neutrophil elastase (NE) translocates to the nucleus during NETosis and cleaves histones, thus aiding in chromatin decondensation. NE(-/-) mice were shown not to release NETs in response to microbes. However, mouse studies evaluating the role of NE in NET formation in sterile inflammation and thrombosis are lacking. OBJECTIVE: We wished to establish if neutrophils from NE(-/-) mice have a defect in NETosis, similar to peptidylarginine deiminase 4 (PAD4(-/-)) mice, and how this might have an impact on venous thrombosis, a model where NETs are produced and are crucial to thrombus development. METHODS: We performed in vitro NET assays using neutrophils from wild-type (WT), NE(-/-), SerpinB1 (SB1)(-/-) and NE(-/-) SB1(-/-) mice. We compared WT and NE(-/-) animals using the inferior vena cava stenosis model of deep vein thrombosis (DVT). RESULTS: Neutrophil elastase deficiency resulted in a small reduction in ionomycin-induced NET formation in vitro without affecting histone citrullination. However, NET production in response to phorbol 12-myristate 13-acetate or platelet activating factor was normal in neutrophils from two independent NE-deficient mouse lines, and in NE(-/-) SB1(-/-) as compared with SB1(-/-) neutrophils. NE deficiency or inhibition did not prevent NETosis in vivo or DVT outcome. CONCLUSIONS: Neutrophil elastase is not required for NET formation in mice. NE(-/-) mice, which form pathological venous thrombi containing NETs, do not phenocopy PAD4(-/-) mice in in vitro NETosis assays or experimental venous thrombosis. Our study suggests that NET-targeted therapies need to be highly effective to have an impact on DVT.

The utilization of recombinant prostanoid receptors to determine the affinities and selectivities of prostaglandins and related analogs.

Stable cell lines that individually express the eight known human prostanoid receptors (EP(1), EP(2), EP(3), EP(4), DP, FP, IP and TP) have been established using human embryonic kidney (HEK) 293(EBNA) cells. These recombinant cell lines have been employed in radioligand binding assays to determine the equilibrium inhibitor constants of known prostanoid receptor ligands at these eight receptors. This has allowed, for the first time, an assessment of the affinity and selectivity of several novel compounds at the individual human prostanoid receptors. This information should facilitate interpretation of pharmacological studies that employ these ligands as tools to study human tissues and cell lines and should, therefore, result in a greater understanding of prostanoid receptor biology.

Tissue factor expressed by circulating cancer cell-derived microparticles drastically increases the incidence of deep vein thrombosis in mice.

BACKGROUND: The risk of thrombotic complications such as deep vein thrombosis (DVT) during tumor development is well known. Tumors release into the circulation procoagulant microparticles (MPs) that can participate in thrombus formation following vessel injury. The importance of this MP tissue factor (TF) in the initiation of cancer-associated DVT remains uncertain. OBJECTIVE: To investigate how pancreatic cancer MPs promote DVT in vivo. METHODS: We combined a DVT mouse model in which thrombosis is induced by flow restriction in the inferior vena cava with one of subcutaneous pancreatic cancer in C57BL/6J mice. We infused high-TF and low-TF tumor MPs to determine the importance of TF in experimental cancer-associated DVT. RESULTS: Both tumor-bearing mice and mice infused with tumor MPs subjected to 3 h of partial flow restriction developed an occlusive thrombus; fewer than one-third of the control mice did. We observed that MPs adhered to neutrophil extracellular traps (NETs), which are functionally important players during DVT, whereas neither P-selectin nor glycoprotein Ib were required for MP recruitment in DVT. The thrombotic phenotype induced by MP infusion was suppressed by hirudin, suggesting the importance of thrombin generation. TF carried by tumor MPs was essential to promote DVT, as mice infused with low-TF tumor MPs had less thrombosis than mice infused with high-TF tumor MPs. CONCLUSIONS: TF expressed on tumor MPs contributes to the increased incidence of cancer-associated venous thrombosis in mice in vivo. These MPs may adhere to NETs formed at the site of thrombosis.

Spouse caregivers' attitudes toward obtaining a diagnosis of a dementing illness.

OBJECTIVES: To examine attitudes of spouse caregivers about the process of obtaining a diagnosis of a dementing illness, including perceived benefits and obstacles to obtaining a diagnosis and suggestions for improving the process. DESIGN: A mail survey of spouse caregivers of dementia patients followed by the Michigan Alzheimer's Disease Research Center. PARTICIPANTS: The 233 spouse caregivers of dementia patients who returned a completed questionnaire. RESULTS: More than three-fourths of the sample rated the following benefits of obtaining a diagnosis as very or extremely important: ruling out other causes of memory or behavior problems, allowing family members to get information about dementia, may qualify my spouse for drug treatment, and will allow me to plan for the future. Primary obstacles included the time required to obtain a diagnosis, the cost of procedures, lack of access to physicians trained to diagnose dementing illnesses, and not receiving a referral from a primary care physician (41.6%, 41.0%, 40.8%, and 24.1% of the sample, respectively, agreed or strongly agreed that the factor posed a barrier to obtaining a diagnosis). Content analysis of responses to two open-ended questions identified problematic or stressful aspects of obtaining a diagnosis and suggestions for making the process easier for the patient and family. CONCLUSION: Results suggest the need to provide an orientation to the diagnosis and assessment process for patients and family members, develop a training session for physicians to better prepare them to address the emotional needs of patients and families and to disclose the diagnosis in an informative and compassionate manner, and provide outreach education to primary care physicians to increase knowledge and awareness of dementing illnesses and to increase referrals to community-based services and health professionals able to address the concerns of family members.

Immunolocalization of the prostaglandin E2 receptor subtypes in human bone tissue: differences in foetal, adult normal, osteoporotic and pagetic bone.

PGE(2) is an important mediator of bone metabolism, but the precise localization of its receptors in human bone remains unknown. The present study used specific antibodies against EP(1), EP(2), EP(3) and EP(4) receptors for immunolocalization in normal, osteoporotic and pagetic human adult bone and in human foetal bone. No labelling was obtained for the EP(1) and EP(2) receptors. The EP(3) receptor was detected in foetal osteoclasts, osteoblasts and osteocytes, but only in osteoclasts and some osteoblasts from adult bone. The EP(4) receptor was detected in foetal osteoclasts, osteoblasts and osteocytes and in adult osteoclasts and osteoblasts, but not in adult osteocytes. Our results show differences in PGE(2) receptor expression in foetal and adult human bone but no difference in adult normal compared to pathologic bone. Finally, these results show that the distribution of EP receptors in human osteoblasts in bone corresponds in part to what we recently described in human osteoblasts in culture.

Impact of social support, social cognitive variables, and perceived threat on depression among adults with diabetes.

Tested was a model of social support and cognitive appraisal of self-efficacy, outcome expectancies, and illness threat on depression. Study participants were community-dwelling adults with diabetes who completed a mailed questionnaire (N = 362). Results of structural equation modeling indicated that 52% of the variance in depression was explained by the model--largely by the direct effects of physical functioning, the perceived availability of social support, and the perceived threat of diabetes as well as the indirect paths from perceived support to perceived threat and from physical functioning to perceived support and perceived threat of diabetes. Diabetes-specific social support, self-efficacy, and outcome expectancies were not significant predictors of depression.

Demonstration of monoclonal anti-carcinoembryonic antigen (CEA) antibody internalization by electron microscopy, western blotting and radioimmunoassay.

One of the important factors affecting the action of monoclonal antibodies (Mabs) or immunoconjugates on tumour sites depends on whether the Mab is internalized by the cancer cells in question. The underexplored subject of internalization is discussed in this paper, and a number of in vitro techniques for investigating internalization are evaluated, using a model which consists of a well characterized anti-carcinoembryonic antigen (anti-CEA) Mab and a number of CEA expressing human cancer cell lines. Employing two alternative radiolabeling assays, evidence for internalization of the anti-CEA Mab by a CEA-positive colorectal cancer cell line (LS174T) was obtained throughout the time intervals examined (5 min to 150 min). Electronmicroscopy employing horseradish-peroxidase labeled anti-CEA Mab and control antibody permitted direct visualization of anti-CEA Mab-related staining in intracellular compartments of a high CEA-expressor human colorectal cell line (SKCO1). Finally Western blots of samples derived from cytosolic and membrane components of solubilized cells from lung and colonic cancer cell lines provided evidence for internalized anti-CEA Mab throughout seven half hour intervals, starting at 5 minutes. Internalized anti-CEA was detected in all CEA expressing cell lines (LS174T, SKCO1, BENN) but not in the case of a very low CEA expressor line (COLO 320).

The costs of caring: impact of dementia on family caregivers.

With the aging of the population, an increasing number of older adults are diagnosed with Alzheimer's disease or a related disorder. Most people with a dementing illness will be cared for at home by a family member, who may experience a variety of physical, emotional, financial, and social burdens associated with the caregiving role. The purpose of this article is to (a) examine the physical and psychological effects of providing care to a family member with a dementing illness, (b) describe the factors that help determine the nature and magnitude of these effects, and (c) discuss several approaches to caregiver intervention designed to reduce the negative impact of this challenging role. Sociodemographic characteristics (e.g., gender, relationship to the patient, culture, race, ethnicity), caregiver resources (e.g., coping, social support, availability of a companion animal), and personal characteristics (e.g., personality, health behaviors) shape the dementia caregiving experience and have implications for interventions designed to prevent or lessen the stress and burden that often accompany the role.

Semi-fixed-length motion vector coding for H.263-based low bit rate video compression.

We present a semi-fixed-length motion vector coding method for H.263-based low bit rate video compression. The method exploits structural constraints within the motion field. The motion vectors are encoded using semi-fixed-length codes, yielding essentially the same levels of rate-distortion performance and subjective quality achieved by H.263's Huffman-based variable length codes in a noiseless environment. However, such codes provide substantially higher error resilience in a noisy environment.

An efficient computation-constrained block-based motion estimation algorithm for low bit rate video coding.

We present an efficient computation constrained block-based motion vector estimation algorithm for low bit rate video coding that yields good tradeoffs between motion estimation distortion and number of computations. A reliable predictor determines the search origin, localizing the search process. An efficient search pattern exploits structural constraints within the motion field. A flexible cost measure used to terminate the search allows simultaneous control of the motion estimation distortion and the computational cost. Experimental results demonstrate the viability of the proposed algorithm in low bit rate video coding applications. The resulting low bit rate video encoder yields essentially the same levels of rate-distortion performance and subjective quality achieved by the UBC H.263+ video coding reference software. However, the proposed motion estimation algorithm provides substantially higher encoding speed as well as graceful computational degradation capabilities.

Predictors of decreased self-care among spouse caregivers of older adults with dementing illnesses.

This study describes the health behaviors (alcohol consumption, exercise, sleep patterns, smoking, and weight maintenance) of a sample of older adult spouse caregivers (N = 233) and investigates the predictors of decreased self-care since caregiving began. Multiple regression results indicate that caregivers who experience greater developmental burden, report a greater number of depressive symptoms, perform a greater number of activities of daily living (ADL) tasks in caregiving and spend more hours in a day providing care, and who have lower self-efficacy for both self-care and spouse care are at greater risk for negative health behavior change. Results have implications for the identification of caregivers who may be particularly vulnerable to the negative health impact of caregiving.

The Prince Edward Island Conceptual Model for Nursing: a nursing perspective of primary health care.

The philosophy of primary health care (PHC) recognizes that health is a product of individual, social, economic, and political factors and that people have a right and a duty, individually and collectively, to participate in the course of their own health. The majority of nursing models cast the client in a dependent role and do not conceptualize health in a social, economic, and political context. The Prince Edward Island Conceptual Model for Nursing is congruent with the international move towards PHC. It guides the nurse in practising in the social and political environment in which nursing and health care take place. This model features a nurse/client partnership, the goal being to encourage clients to act on their own behalf. The conceptualization of the environment as the collective influence of the determinants of health gives both nurse and client a prominent position in the sociopolitical arena of health and health care.

Measurement of social interaction in change of health behavior.

A social network approach to measuring social interaction related to change of health behavior required 460 participants in a health promotion program to nominate up to five network members and to rate the supportiveness of each person in changing health behavior during the previous year. Exploratory factor analysis of intercorrelations of the eight items suggested two factors representing supportive and negative interaction with internal consistency reliability of .89 and .61, respectively.

Limits on Medicaid program fund transfers.

Recent Federal legislation has curtailed many of the so-called creative ways states previously used to fund their Medicaid programs. Specifically, the Medicaid Voluntary Contributions and Provider-Specific Tax Amendments of 1991 prevent states from using voluntary donations and taxes on healthcare providers to obtain increased Federal matching funds. In the future, therefore, many state governments may be forced to make a difficult choice between either increasing taxes significantly to finance health care for the poor or drastically reducing Medicaid rates and coverage.