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L Kessler

Publications and source records attributed to L Kessler.

At least 37 records · Page 2Linked to original sources
PubMed1996

Cytotoxicity of peritoneal murine macrophages against encapsulated pancreatic rat islets: in vivo and in vitro studies.

The aim of this work was to study in vivo and in vitro the involvement of macrophages and interleukin-1beta (IL-1beta) in the necrosis of encapsulated islets during xenograft and to evaluate the immunoprotective efficiency of the AN69 membrane. In vivo, 6 days after implantation, 65% of the membrane surface of the devices containing the islets was colonized with macrophages compared with only 5% of the surface of the empty control devices. The morphological aspect of implanted islets was altered and their insulin release decreased significantly compared with freshly isolated ones (265 +/- 50 vs. 507 +/- 81 microU/mL). In vitro, the insulin release of encapsulated islets cultured for 2 days decreased to 32 and 28%, respectively, in the presence of IL-1beta and macrophages. The addition of anti-IL-1beta antibody to the co-culture of macrophages and islets did not modify this loss of functional activity. Furthermore, IL-1beta passed through the AN69 membrane. In conclusion, macrophages are involved in damaging encapsulated pancreatic islets and are probably partly responsible for islet transplantation failure.

Animals↗
PubMed1996

[Benefits and limitations of pancreas transplantation in insulin-dependent diabetics: a study apropos of 26 patients].

From November 1990 to March 1995, 26 simultaneous pancreas-kidney (SPK) transplants were carried out. The recipients were uremic type I diabetic patients. After the first year of transplantation, patient survival was 96% and pancreas and kidney survival was 69% and 84%, respectively. The pancreas transplant failure was due to veinous thrombosis (two cases), and to graft rejection (71%). The most common urologic complications of bladder drainage were urethritis (61%), bicarbonate loss (42%) and urinary tract infections (100%). Fasting blood glucose (0.91 +/- 0.1 g/L), hemoglobin A1C (5.3 +/- 0.4%) and lipidic profile were found to be normal among diabetic recipients whose grafts had been functioning for 1 year. The insulin secretion of type I diabetic patients with SPK transplants (n = 13), and six non diabetic patients with kidney transplants was assessed by oral glucose tolerance tests. Only the patients with SPK transplants presented late hyperinsulinemia at 120 minutes. The quality of life for both type I diabetic patients after SPK transplants and diabetics treated by insulinotherapy (n = 6), was studied. After transplantation, the quality of life improved only because of insulin independence. In spite of chirurgical and urologic complications, pancreas transplantation in type I diabetic patients improves both metabolic control and quality of life.

Adult↗
PubMed1996

Nasopharyngeal carcinoma: an EBV-associated tumour not significantly influenced by HIV-induced immunosuppression. The AIDS/Cancer Working Group.

We used a link between cancer (859,398 reports) and AIDS (50,050 reports) registries in the United States to study whether nasopharyngeal carcinoma (NPC) was increased in the population with AIDS. There was no indication of a significantly increased risk up to or after the AIDS diagnosis, which argues against progressively failing immunity being important in the development of this malignancy.

Adult↗
PubMed1996

Pancreatic islet macroencapsulation: a new device for the evaluation of artificial membrane.

We propose a new device especially designed to test membranes for islet macroencapsulation. It is composed of three independent parts: a support made of three polytetrafluoroethylene rings, the membrane that forms the walls of the encapsulation chamber, and a collagen gel that immobilizes the islets. Studies of this device were performed with the AN69 membrane. After 2 months of implantation in the peritoneal cavity of rats, the empty device was found to be biocompatible, referred to as weak cellular adhesion. In vitro the encapsulation preserved the peak of insulin release in response to high glucose during a perifusion test (0.36 +/- 0.02 microU/ml/islet for free or encapsulated islets). As a result of the collagen gel, the morphological aspect and functional activity were still preserved after 7 days of culture. In vivo xenotransplantation into diabetic mice normalized the fasting glycemia up to 30 days. Numerous macrophages adhered to the outer surface of the membrane, and a layer of cells emerging from the destruction of islets covered the inner surface. In addition, the morphological aspect of many islets was altered. By showing that the AN69 membrane was only partially efficient for islet xenotransplantation, this new device proved to be of interest for testing a variety of membranes.

Acrylic Resins↗
PubMed1996

A community development and outreach program in geriatric mental health: four years' experience.

OBJECTIVES: To describe a geriatric mental health outreach program based on a community development model and to review 4 years of experience with this program. DESIGN: Program model and description of implementation experience. SETTINGS: A geriatric mental health outreach program of a regional psychiatric hospital, serving a primarily non-urban area, with offices in the community it serves. PARTICIPANTS: The program targets community-dwelling or institutionalized older persons with late-onset mental health problems and/or behavioral disturbances, persons with long-standing psychiatric disorders with age-related changes, and their caregivers. INTERVENTION: The program is a geriatric mental health outreach and consultation service that emphasizes community development and caregiver education. Program components include an interprofessional consultation team, a specialized information and resource service, educational service initiatives, and an ongoing role in planning and coordination activity in the local health care system. MEASUREMENTS: Program monitoring, including a patient database and a description of program activities. RESULTS: Cognitive impairment, behavioral disturbance, physical/medical problems and depression are the most common reasons for referral to the outreach program. Referred patients (mean age 78; 65% female) have usually (almost 90% of cases) been managed at a similar or lower level of care. Program activities have included focused educational initiatives in community and institutional settings and have emphasized the involvement and development of community caregivers and other local resources. CONCLUSION: The program is a multifaceted effort to make efficient use of scarce specialized resources in a manner that is sensitive and responsive to local circumstances and needs. Experience to date has shown evidence of the feasibility and potential benefits of a comprehensive approach to community development and outreach in geriatric mental health.

Aged↗
PubMed1995

Influence of corona surface treatment on the properties of an artificial membrane used for Langerhans islets encapsulation: permeability and biocompatibility studies.

An artificial membrane (AN69 Hospal) suitable for pancreatic islets encapsulation was submitted to a physicochemical treatment (corona discharge) to improve its insulin permeability. This effect depends on the duration of the electrical discharge (expressed as the speed of a conveyor belt) and the distance between the electrodes and the membrane. Among the various treatments tested, the most efficient (distance of 5 cm and a speed of 2 cm s-1) produced a three-fold increase in insulin diffusion. This improvement persisted after a protein-coating test which mimics in vivo conditions. At 1 y after the peritoneal implantation, the corona-treated membrane remained biocompatible. Thus, corona discharge treatment may serve to optimize the properties of artificial membranes used for pancreatic islets encapsulation.

Animals↗
PubMed1995

Discovery method and stage of breast cancer in two different patient populations.

Our purpose was to determine the discovery method and stage of newly discovered breast cancers at two different medical centers. To do this, we conducted a retrospective chart review at our urban and suburban teaching hospitals during 1991 through 1992 and 1992, respectively. Only 29 (26%) of 112 cancers at our urban hospital were discovered mammographically; 38 (38%) of 100 neoplasms were discovered using mammography at our suburban hospital. At both institutions, the mammographically discovered cancers had a lower stage than those detected clinically. Despite proven benefits and the efforts of organizations such as the American College of Radiology and the American Cancer Society, screening mammography remains underused in the patient populations that we studied.

Adult↗
PubMed1994

High incidence of anal cancer among AIDS patients. The AIDS/Cancer Working Group.

Until now, the only cancers that have been strongly associated with AIDS are Kaposi's sarcoma and non-Hodgkin lymphoma. We used a linkage between AIDS (50,050 reports) and cancer (859,398 reports) registries in seven health departments in the USA to investigate the association between HIV infection and epidermoid anal cancer. We compared the numbers of observed cases and expected cases, calculated from general population rates with adjustment for age, sex, and race. The relative risk of anal cancer at and after AIDS diagnosis was 84.1 (95% CI 46.4-152) among homosexual patients (11 cases) and 37.7 (9.4-151) among non-homosexual patients (2 cases). The relative risk of anal cancer up to 5 years before the AIDS diagnosis (23 cases) was also increased; it was 13.9 (6.6-29.2) in the period 2-5 years before AIDS and 27.4 (15.9-47.2) during the 2 years before AIDS diagnosis (p for trend = 0.004). Among homosexual men, the relative risk of anal cancer was inversely related to age at AIDS onset (p for trend < 0.001). Excess risks were found in all geographical areas. This study establishes a strikingly increased risk of anal cancer among people with AIDS. These data are consistent with a previously hypothesized association between HIV-induced immunodeficiency and anal cancer development, but because homosexual men were at increased risk of anal cancer even before the AIDS epidemic, we cannot say how much of the increased risk is attributable to HIV infection. Nevertheless, clinicians should be aware that AIDS patients have an increased risk of anal cancer.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Rapid activation of the interferon-gamma signal transduction pathway by inhibitors of tyrosine phosphatases.

Induction of gene expression by interferon-gamma involves the activation of a latent cytoplasmic transcription factor, p91, by phosphorylation on a single tyrosyl residue. This phosphorylation triggers dimerization, nuclear translocation, and the binding of p91 to interferon-gamma response elements present in the promoters of induced genes. Phosphorylation of p91 requires the activation of two tyrosine kinases, JAK1 and JAK2, that themselves become phosphorylated on tyrosyl residues shortly after interferon-gamma binds to its receptor. The importance of tyrosine phosphorylation in this pathway prompted us to investigate the role of protein tyrosine phosphatases in the regulation of the pathway. We find that in the absence of interferon-gamma, treatment of cells with an inhibitor of tyrosine phosphatases causes a rapid and potent activation of the components of the interferon-gamma signal transduction pathway and induces an interferon-gamma-responsive gene. This suggests that tyrosine phosphatases act both to repress the interferon-gamma signal transduction pathway in the absence of interferon-gamma and to downregulate the pathway after interferon-gamma induction.

Base Sequence↗
PubMed1994

Geriatric psychiatry consultation in the community.

While increasing emphasis is being placed on geriatric psychiatry consultation and outreach services, there is considerable variation in terms of the composition and direction of these programs. Programs vary in terms of their objectives, location, target population, use of health professions and other resources and their method of consultation. The purposes of this paper are to review the characteristics of existing programs, to review the needs of the targets of consultation and to consider theoretical and methodological approaches which have been found to be useful in mental health/psychiatric consultation, in continuing medical education, and in program evaluation. On the basis of this review, future directions for effective approaches to consultative outreach in geriatric psychiatry will then be proposed.

Aged↗
PubMed1994

Changes in the use of screening mammography: evidence from the 1987 and 1990 National Health Interview Surveys.

OBJECTIVES: Mammography rates reported by women in the National Health Interview Surveys of 1990 and 1987 are examined. Why this screening modality is not more frequently used is explored. METHODS: Data from the 1987 and 1990 National Health Interview Surveys, conducted by the National Center for Health Statistics, are cross-tabulated and compared. RESULTS: In 1987, approximately 17% of women over 40 years of age reported having had a screening mammogram in the previous year. In 1990, the rate doubled. Race declined in importance; income and education remained strong, positive predictors of screening. CONCLUSIONS: Despite this dramatic increase, two thirds of women are not having screening mammograms. Use was not higher primarily because women did not realize that screening mammography tests for breast cancer in asymptomatic women. Primary care physicians are the main source of health education for screening mammography. The data suggest that public health programs to promote screening mammography should especially target primary care physicians and women with low incomes and education. Likewise, health care providers should ensure that their patients are referred to facilities that deliver high-quality mammography at low cost to make the procedure more accessible.

Adult↗
PubMed1994

Emotional support following cancer: a test of the stigma and social activity hypotheses.

Reports of changes in emotional support following surgery for breast cancer can be attributed to one of two factors: (1) the stigma associated with cancer, or (2) illness-imposed restrictions in one's activities. These explanations were assessed using data from a longitudinal study of women, following their surgical treatment for early breast cancer (N = 145), gallbladder disease (N = 90), benign breast disease (N = 87), or no surgery (N = 90). Multiple regression analysis was used to test the two models. Contrary to the cancer stigma hypothesis, women with breast cancer initially perceived themselves to have more emotional support, rather than less. Type of surgery did not explain the level of emotional support as post-surgery time increased. Instead, support for the social activity hypothesis was found. The results are interpreted as indicating that breast cancer no longer carries with it a stigma, at least not to the extent of reducing the level of women's emotional support.

Activities of Daily Living↗
PubMed1993

The Cancer Information Service Telephone Evaluation and Reporting System (CISTERS): a new tool for assessing quality assurance.

With more than 500,000 annual telephone inquiries from the public, health professionals, and others, the toll-free telephone-based Cancer Information Service (CIS) has rapidly evolved into a primary contact point and resource for people seeking cancer-related information. As the CIS continues to grow, quality-assurance issues are increasingly important both to maintain a high quality of responses to callers and to ensure the accuracy of information transmitted. The Cancer Information Service Telephone Evaluation and Reporting System (CISTERS), a computer-based interactive interviewing system, is being developed to provide quantitative measures of various aspects of the quality of CIS responses to telephone inquiries. In addition to supplying quantitative feedback to both the National Cancer Institute (NCI) CIS office and the regional CIS offices, CISTERS also allows program managers to identify and provide for staff training needs. CISTERS is a substantial part of NCI's commitment to quality control and assessment of needs within the CIS network and may have significant implications for the growing number of other national telephone-based, health-information helplines.

Humans↗
PubMed1992

Diffusion properties of an artificial membrane used for Langerhans islets encapsulation: an in vitro test.

Glucose and insulin permeability of an artificial membrane (AN69, HOSPAL, Sweden) used for Langerhans islets encapsulation were investigated. In vivo, a 1 and 7 d intraperitoneal implantation of the AN69 membrane in rats induced a loss of permeability towards glucose and insulin probably due to a protein-coating performed after implantation. In vitro, a protein-coating of the AN69 membrane with fetal calf serum solution reproduced similar results. Thus this in vitro test which mimicks in vivo conditions should be proposed to evaluate rapidly the physicochemical properties of a membrane suitable for pancreatic islets encapsulation.

Acrylic Resins↗