Pharmacological Modulation of the Wnt/β-Catenin Pathway Inhibits Proliferation and Promotes Differentiation of Long-Lived Memory CD4+ T Cells in Antiretroviral Therapy-Suppressed Simian Immunodeficiency Virus-Infected Macaques

The major obstacle to human immunodeficiency type 1 virus (HIV-1) eradication is a reservoir of latently infected cells that persists despite long-term antiretroviral therapy (ART) and is maintained through cellular proliferation. Long-lived memory CD4+ T cells with high self-renewal capacity, such as central memory (CM) T cells and stem cell memory (SCM) T cells, are major contributors to the viral reservoir in HIV-infected individuals on ART. The Wnt/β-catenin signaling pathway regulates the balance between self-renewal and differentiation of SCM and CM T cells, and pharmacological manipulation of this pathway offers an opportunity to interfere with the proliferation of latently infected cells. Here, we evaluated in vivo a novel approach to inhibit self-renewal of SCM and CM CD4+ T cells in the rhesus macaque (RM) model of simian immunodeficiency (SIV) infection. We used an inhibitor of the Wnt/β-catenin pathway, PRI-724, that blocks the interaction between the coactivator CREB-binding protein (CBP) and β-catenin, resulting in the cell fate decision to differentiate rather than proliferate. Our study shows that PRI-724 treatment of ART-suppressed SIVmac251-infected RMs resulted in decreased proliferation of SCM and CM T cells and modified the SCM and CM CD4+ T cell transcriptome toward a profile of more differentiated memory T cells. However, short-term treatment with PRI-724 alone did not significantly reduce the size of the viral reservoir. This work demonstrates for the first time that stemness pathways of long-lived memory CD4+ T cells can be pharmacologically modulated in vivo, thus establishing a novel strategy to target HIV persistence.IMPORTANCE Long-lasting CD4+ T cell subsets, such as central memory and stem cell memory CD4+ T cells, represent critical reservoirs for human immunodeficiency virus (HIV) persistence despite suppressive antiretroviral therapy. These cells possess stem cell-like properties of enhanced self-renewal/proliferation, and proliferation of latently infected memory CD4+ T cells plays a key role in maintaining the reservoir over time. Here, we evaluated an innovative strategy targeting the proliferation of long-lived memory CD4+ T cells to reduce viral reservoir stability. Using the rhesus macaque model, we tested a pharmacological inhibitor of the Wnt/β-catenin signaling pathway that regulates T cell proliferation. Our study shows that administration of the inhibitor PRI-724 decreased the proliferation of SCM and CM CD4+ T cells and promoted a transcriptome enriched in differentiation genes. Although the viral reservoir size was not significantly reduced by PRI-724 treatment alone, we demonstrate the potential to pharmacologically modulate the proliferation of memory CD4+ T cells as a strategy to limit HIV persistence.

MAP4K4 Inhibition Promotes Survival of Human Stem Cell-Derived Cardiomyocytes and Reduces Infarct Size In Vivo

Heart disease is a paramount cause of global death and disability. Although cardiomyocyte death plays a causal role and its suppression would be logical, no clinical counter-measures target the responsible intracellular pathways. Therapeutic progress has been hampered by lack of preclinical human validation. Mitogen-activated protein kinase kinase kinase kinase-4 (MAP4K4) is activated in failing human hearts and relevant rodent models. Using human induced-pluripotent-stem-cell-derived cardiomyocytes (hiPSC-CMs) and MAP4K4 gene silencing, we demonstrate that death induced by oxidative stress requires MAP4K4. Consequently, we devised a small-molecule inhibitor, DMX-5804, that rescues cell survival, mitochondrial function, and calcium cycling in hiPSC-CMs. As proof of principle that drug discovery in hiPSC-CMs may predict efficacy in vivo, DMX-5804 reduces ischemia-reperfusion injury in mice by more than 50%. We implicate MAP4K4 as a well-posed target toward suppressing human cardiac cell death and highlight the utility of hiPSC-CMs in drug discovery to enhance cardiomyocyte survival.

PDGFRα demarcates the cardiogenic clonogenic Sca1+ stem/progenitor cell in adult murine myocardium

Cardiac progenitor/stem cells in adult hearts represent an attractive therapeutic target for heart regeneration, though (inter)-relationships among reported cells remain obscure. Using single-cell qRT-PCR and clonal analyses, here we define four subpopulations of cardiac progenitor/stem cells in adult mouse myocardium all sharing stem cell antigen-1 (Sca1), based on side population (SP) phenotype, PECAM-1 (CD31) and platelet-derived growth factor receptor-α (PDGFRα) expression. SP status predicts clonogenicity and cardiogenic gene expression (Gata4/6, Hand2 and Tbx5/20), properties segregating more specifically to PDGFRα(+) cells. Clonal progeny of single Sca1(+) SP cells show cardiomyocyte, endothelial and smooth muscle lineage potential after cardiac grafting, augmenting cardiac function although durable engraftment is rare. PDGFRα(-) cells are characterized by Kdr/Flk1, Cdh5, CD31 and lack of clonogenicity. PDGFRα(+)/CD31(-) cells derive from cells formerly expressing Mesp1, Nkx2-5, Isl1, Gata5 and Wt1, distinct from PDGFRα(-)/CD31(+) cells (Gata5 low; Flk1 and Tie2 high). Thus, PDGFRα demarcates the clonogenic cardiogenic Sca1(+) stem/progenitor cell.

In vivo mapping of vascular inflammation using the translocator protein tracer 18F-FEDAA1106

Noninvasive imaging methods are required to monitor the inflammatory content of atherosclerotic plaques. FEDAA1106 (N-(5-fluoro-2-phenoxyphenyl)-N-(2-(2-fluoroethoxy)-5-methoxybenzyl) acetamide) is a selective ligand for TSPO-18kDa (also known as peripheral benzodiazepine receptor), which is expressed by activated macrophages. We compared 18F-FEDAA1106 and 2-deoxy-2-[18F]fluoro-d-glucose (18F-FDG, a marker of glucose metabolism) for positron emission tomographic (PET) imaging of vascular inflammation. This was tested using a murine model in which focal inflammation was induced in the carotid artery via placement of a constrictive cuff. Immunostaining revealed CD68-positive cells (macrophages) at a disturbed flow site located downstream from the cuff. Dynamic PET imaging using 18F-FEDAA1106 or 18F-FDG was registered to anatomic data generated by computed tomographic (CT)/CT angiography. Standardized uptake values were significantly increased at cuffed compared to contralateral arteries using either 18F-FEDAA1106 (p < .01) or FDG (p < .05). However, the 18F-FEDAA1106 signal was significantly higher at the inflamed disturbed flow region compared to the noninflamed uniform flow regions, whereas differences in FDG uptake were less distinct. We conclude that 18F-FEDAA1106 can be used in vivo for detection of vascular inflammation. Moreover, the signal pattern of 18F-FEDAA1106 corresponded with vascular inflammation more specifically than FDG uptake.

Efficient broadband 400 nm noncollinear second-harmonic generation of chirped femtosecond laser pulses in BBO and LBO

We report on 400 nm broadband type I frequency doubling in a noncollinear geometry with pulse-front-tilted and chirped femtosecond pulses (λ =800  nm; Fourier transform limited pulse duration, 45 fs). With moderate power densities (2 to 10  GW/cm2) thus avoiding higher-order nonlinear phenomena, the energy conversion efficiency was up to 65%. Second-harmonic pulses of Fourier transform limited pulse duration shorter than the fundamental wave were generated, exhibiting good beam quality and no pulse-front tilt. High energy (20 mJ/pulse) was produced in a 40 mm diameter and 6 mm thick LBO crystal. To the best of our knowledge, this is the first demonstration of this optical configuration with sub-100-fs pulses. Good agreement between experimental results and simulations is obtained.

T₁ mapping detects pharmacological retardation of diffuse cardiac fibrosis in mouse pressure-overload hypertrophy

BACKGROUND

Diffuse interstitial fibrosis is present in diverse cardiomyopathies and associated with poor prognosis. We investigated whether magnetic resonance imaging-based T1 mapping could quantify the induction and pharmacological suppression of diffuse cardiac fibrosis in murine pressure-overload hypertrophy.

METHODS AND RESULTS

Mice were subjected to transverse aortic constriction or sham surgery. The angiotensin receptor blocker losartan was given to half the animals. Cine-magnetic resonance imaging performed at 7 and 28 days showed hypertrophy and remodeling and systolic and diastolic dysfunction in transverse aortic constriction groups as expected. Late gadolinium-enhanced magnetic resonance imaging revealed focal signal enhancement at the inferior right ventricular insertion point of transverse aortic constriction mice concordant with the foci of fibrosis in histology. The extracellular volume fraction, calculated from pre- and postcontrast T1 measurements, was elevated by transverse aortic constriction and showed direct linear correlation with picrosirius red collagen volume fraction, thus confirming the suitability of extracellular volume fraction as an in vivo measure of diffuse fibrosis. Treatment with losartan reduced left ventricular dysfunction and prevented increased extracellular volume fraction, indicating that T1 mapping is sensitive to pharmacological prevention of fibrosis.

CONCLUSIONS

Magnetic resonance imaging can detect diffuse and focal cardiac fibrosis in a clinically relevant animal model of pressure overload and is sensitive to pharmacological reduction of fibrosis by angiotensin receptor blockade. Thus, T1 mapping can be used to assess antifibrotic therapeutic strategies.

Low energy prepulse for 10 Hz operation of a soft-x-ray laser

The influence on Nickel-like Molybdenum soft-x-ray laser performance and stability of a low energy laser prepulse arriving prior to the main laser pumping pulses is experimentally investigated. A promising regime for 10 Hz operation has been observed. A four times increase in soft-x-ray laser operation time with a same target surface is demonstrated. This soft-x-ray laser operation mode corresponds to an optimum delay between the prepulse and the main pulses and to a prepulse energy greater than 20 mJ. We also show that this regime is not associated with a weaker degradation of the target or any reduced ablation rate. Therefore the role of preplasma density gradient in this effect is discussed.

Fourier-limited seeded soft x-ray laser pulse

We present what we believe to be the first measurement of the spectral properties of a soft x-ray laser seeded by a high-order harmonic beam. Using an interferometric method, the spectral profile of a seeded Ni-like krypton soft x-ray laser (32.8 nm) generated by optical field ionization has been experimentally determined, and the shortest possible pulse duration has been deduced. The source exhibits a Voigt spectral profile with an FWHM of 3.1+/-0.3 mA, leading to a Fourier-transform pulse duration of 4.7 ps. This value is comparable with the upper limit of the soft x-ray pulse duration determined by experimentally investigating the gain dynamics, from which we conclude that the source has reached the Fourier limit. The measured bandwidth is in good agreement with the predictions of a radiative transfer code, including gain line narrowing and saturation rebroadening.

A model of the impact of immigration on health and social service expenditures for the elderly

"Immigration, primarily from the former Soviet Union, has swelled the population of Israel by 10% between 1990 and 1993 and total population growth by the end of the decade is expected to be over 30%. The research presented here represents part of a larger effort to project needs and costs for the entire population in order to assist health and social welfare services in planning and resource allocation. The paper presents an overview of the current demographic situation in Israel, a theoretical model for estimating the growth in needs, and estimates of needs and costs for services for the elderly population based upon this model."

New developments and issues in home care policies

This paper provides an overview of the major trends in the organization of services for the disabled elderly, and the implications for the elderly of the emphasis in recent years on remaining at home in the community. The paper presents an example of changing policies from the experience of Israel, which recently enacted a Community Long-term Care Insurance Law to increase levels of home care entitlements to the severely disabled.

A prospective study of the repeated use of sterilized papillotomes and retrieval baskets for ERCP: quality and cost analysis

BACKGROUND

The impact on instrument quality and cost of the practice of reusing ERCP accessories has not been fully addressed.

METHODS

Twenty-five new papillotomes and 15 new retrieval baskets were labeled and evaluated over time by staff blinded to the number of prior uses. Instruments were scored as to their function for the designated task. The cost of this practice was calculated from the purchase price of accessories and the costs of cleaning, sterilization, and disposal, and then compared with the estimated cost of a practice of one-time use of similar instruments.

RESULTS

Twenty-five papillotomes were used 246 times (median 8; mean 9.8). Fifteen retrieval baskets were used 193 times (median 13; mean 12.9). The median survival of both papillotomes and baskets before being considered inadequate (score < 6 out of 10) was 9 uses. There were no complications attributable to using reused equipment. The projected yearly cost savings of using reusable versus disposable instruments was $94,095 for papillotomes and $61,809 for baskets, a 475% and 322% cost reduction, respectively.

CONCLUSION

The papillotomes and baskets in this study could be reused reliably and safely multiple times, with considerable cost savings compared with the practice of using disposable instruments.

Quality management for health care in the Middle East and north Africa: professional cooperation as part of the peace process

BACKGROUND

In 1993, as the peace process opened up new possibilities for professional cooperation, the Quality Management (QM) Program for Health Care Organizations in the Middle East and North Africa was born of a shared perception that there is a high-priority need to improve the quality of health care and to cope with increasing costs and financial pressures. To date 22 health care organizations--including hospitals, primary care centers, health maintenance organizations, and ministries of health--are members of the QM Program and are actively implementing QM projects.

DEVELOPMENT OF THE PROGRAM

The QM Program began with an introductory conference, followed by an intensive training course. During the current phase of the program (1996-1999), a variety of facilitation activities--including training visits to the region by international experts, consultation support to member organizations by volunteer mentors in the United States, professional-exchange seminars, and site visits--are being conducted at the regional and national levels. Since the training course, the QM Program member organizations have implemented more than 40 model QM projects to improve both clinical and nonclinical processes. Projects consistent with national and organizational priorities were selected, with an emphasis on fast-paced improvements that reduce costs and enhance patient satisfaction.

FUTURE PLANS

The regional QM Program is envisioned to grow in size and strength through a four-year building process. By the year 2000, a cadre of local leaders should be prepared to carry the program forward into the new millennium.

Work satisfaction and health in the middle-aged and elderly

BACKGROUND

There is evidence that occupational factors that cause psychological strain can affect physical and mental health, but findings are not consistent.

METHODS

Work satisfaction was used as a convenient global index of job-related psychological strain. Relationships with general, physical and emotional health, appraised by the use of questions, were examined in workers aged > or = 50 years in a longitudinal community health study in Jerusalem.

RESULTS

Positive associations were found both in 1975-1976 and in 1985-1987, with age, origin, education, sex and other variables controlled. The odds ratio in favour of poor general health was 2.8 times as high in dissatisfied workers as in very satisfied ones. Multivariate analyses suggested that the associations were not spurious ones attributable to a proneness to report both dissatisfaction and ill-health. Workers who expressed dissatisfaction in both 1975-1976 and 1985-1987 were particularly unhealthy in 1985-1987.

CONCLUSIONS

The findings support the impact of work satisfaction or its determinants on current health, and suggest that persistent dissatisfaction may be especially deleterious to health.

Understanding the pattern of support for the elderly: a comparison between Israel and Sweden

Cross-cultural comparison can offer critical input to analyses of the interplay between formal and informal services for the elderly. Israel and Sweden have very different population structures and represent different points on the spectrum of welfare state development: Sweden has a much higher percentage of elderly, a less traditional family structure, and a much more developed system of public support. In addition, there are thought to be different attitudes toward family ties, with a less family-oriented value structure in Sweden. The natural question is to what extent these differences translate into differences in the extent and nature of family support for the elderly. In this article, family structure, living arrangements, disability rates, and formal and informal sources of help in Sweden and Israel are compared at various points in time. While there is a greater rate of formal service provision in Sweden and some substitution for family support seems to have occurred, informal care has nevertheless remained important. In both countries, residential patterns are critical: it is when the elderly live alone that the formal system has tended to replace the family. The rate of institutionalization is particularly important in determining the rate of disabled elderly requiring care, both formal and informal, in the community.

Developing an information base for short-and long-term planning of services for the elderly in Israel: an interim report

Population aging throughout the Western world has stimulated a concern with the implications for service needs. It has been increasingly recognized that not only the increase in the total number of elderly, but also changes in their composition, are affecting service needs. This paper describes the attempts made to acquire more detailed information on the implications of demographic change for service needs in Israel. It indicates the dimensions of demographic change and then proceeds to present an overall picture of the strategy employed to evaluate the impact of these changes on aspects of health status and the need for community and institutional services.

Role of institutional and community services in meeting the long-term care needs of the elderly in Israel: the decade of the 1980s

Israel faces a major challenge to its capacity to deal adequately with the needs of the chronically ill. This paper describes the present state of long-term care services for the chronically ill and documents the extensive disparities in the rate of institutional and community services by region. In view of the expected dramatic increase in the number of aged greater than or equal to 75 years old (from 106,800 to 181,500 between 1980 and 1990), the authors project a 50% increase in the need for institutional and community services just to maintain existing service patterns. The paper discusses the central issues related to the development of both types of services in response to the increase in needs.

Evaluation of a community program for the control of cardiovascular risk factors: the CHAD program in Jerusalem

A community-focused program for the control of cardiovascular risk factors, the CHAD program, was instituted in a family practice in western Jerusalem in 1971. Its effectiveness was evaluated by comparing the changes detected by surveys conducted in 1970 and 1975 with those observed in an adjacent control neighborhood. Hypertension decreased in prevalence by 33%, hypercholesterolemia by 31%, cigarette smoking by 23% (among men), and overweight by 13%. Allowing for the reductions observed in the control population, the net percent reductions in prevalence were 20% for hypertension, 15% for hypercholesterolemia, 11% for cigarette smoking (men) and 13% for overweight. The net reductions in hypertension, smoking and overweight were statistically significant. The net reductions in mean systolic and diastolic pressures and weight were also significant. The results suggest that intervention centered in primary health care can have an appreciable effect on cardiovascular risk factors in the population.

A community program for the control of cardiovascular risk factors: a preliminary evaluation of the effectiveness of the CHAD program in Jerusalem

A community program for the control of cardiovascular risk factors, the CHAD program, was instituted in a family practice in western Jerusalem in 1971. The effectiveness of the program was evaluated by comparing the findings of community surveys conducted in 1970 and 1975 and by comparing the changes with those observed in an adjacent control neighborhood. This paper reports the findings among men aged 35 years and above. In the community exposed to the program there was a decrease in mean systolic and disatolic pressures, in the prevalence of hypercholesterolemia, and in the prevalence of cigarette smoking. The changes in blood pressures and smoking habits were significantly greater than those observed in the control population. In the control population (only) there was a small increase in mean body weight and a decrease in reported physical activity. The findings suggest that it is possible for a program that operates and through primary health care to have an appreciable influence upon cardiovascular risk factors in the community.