Concordance in communication between surgeon and patient

PURPOSE: To describe adolescents' and young adults' knowledge about their health insurance, and to identify factors associated with correct knowledge of health insurance in this population. METHODS: Data were analyzed from a confidential questionnaire administered to 830 patients at a hospital-based adolescent medicine clinic. The questionnaire contained items pertaining to insurance type, demographics, health status, and health-risk behaviors. Actual health insurance data and information regarding utilization of health services were obtained from the hospital billing data-base. Predictors of health insurance knowledge were determined through bivariate analyses followed by stepwise logistic regression. RESULTS: A total of 50.7% of respondents correctly identified their type of health insurance. Those who correctly identified their insurance had a higher mean age. Only 48.5% of participants who were 11-18 years old could identify their insurance type, versus 53.1% of 19-21-year-olds and 64.7% of 22-24-year-olds (p = 0.02). Sixty-five percent of Medicaid patients and 76.3% of hospital free care patients knew how their medical bills were paid, versus 17.9% of self-pay patients and 47.3% of patients with private insurance (p < 0.01). Greater utilization of health services was associated with increased rates of insurance knowledge among 19-24-year-olds on bivariate analysis; however, this factor was not significant when controlling for other factors. Regression analysis revealed that older age and insurance type other than self-payment were independent predictors of health insurance knowledge in adolescents (11-18 years old), while female gender and insurance type other than self-payment were independent predictors of insurance knowledge in young adults (19-24 years old). CONCLUSIONS: Approximately half of adolescents and young adults do not know how their medical bills are paid. Validation of self-reported insurance data is, therefore, critical both in clinical practice and health services research.     

The Australian brushtail possum (Trichosurus vulpecula) gonadotrophin alpha-subunit: analysis of cDNA sequence and pattern of expression

Substantial evidence has accumulated to suggest that in the near future implementation of the veto-cell-suppressor concept in the treatment of kidney allograft recipients might lead to the establishment of life-long specific allograft tolerance in the absence of further immunosuppressive therapy. Veto suppression prevents the generation of antigen-specific T-helper and cytotoxic T lymphocytes in vitro provided that the T-lymphocyte precursors specifically recognize antigenic peptides associated with the major histocompatibility complex molecules class II and class I, respectively, expressed on the surface of the veto-active cell. Data from a large number of experimental and clinical studies strongly indicate that veto-active cells function in vivo and are capable of preventing allograft rejection. Thus, donor-cell-mediated veto activity is the most likely explanation for the well-known graft tolerizing effect of pretransplant donor blood transfusions in kidney graft recipients. A prerequisite for a veto-active environment in vivo is the establishment of lymphoid microchimerism, in which veto-active donor and recipient cells mutually downregulate potential alloaggression.     

Immunohistochemical and radiologic study of the accumulation of antibodies to the beta-1-MA antigen in human tumors transplanted into athymic mice

Human tumours and tissues of nude mice were studied immunohistochemically using rabbit antibody to the beta-1-MA. Specific reaction was observed in colonic carcinomas, beta-1-MA was not found in other tumours. The specific reaction was found in intestinal epithelium of nude mice, and was absent in other tissues. 131I-labelled antibody to the beta-1-MA was intravenously administered to tumour-bearing nude mice. Specifically connected antibodies were revealed by immunohistochemical method in colonic carcinomas only. Radioimmunological investigation has shown accumulation of 131I-labelled antibodies to the beta-1-MA in colonic carcinomas.     

The calibration of CERL-Planer capacitance strain gauges

CEGB-Planer capacitance strain gauges are used extensively for monitoring the deformation of components operating in the creep range. However, there are significant differences between the way the gauges are installed for use and the way they are installed for calibration. This paper describes the various types of calibrations that have been carried out to identify the errors associated with these differences and the results show that, providing the manufacturers' recommendations are adhered to, the errors are acceptably small.     

Spatial and temporal expression of angiogenic molecules during tumor growth and progression

The growth and metastasis of cancer directly correlates with tumor angiogenesis. A better understanding of the expression of regulatory factors controlling angiogenesis is important in exploiting this process therapeutically. Our present study demonstrates that small tumors (3-4 mm in diameter) express more basic fibroblast growth factor (bFGF) and interleukin 8 (IL-8) than large tumors (> 10 mm in diameter), whereas more vascular endothelial growth factor (VEGF) is expressed in large tumors. Immunostaining showed a heterogeneous distribution of angiogenic factors within the tumor; expression of bFGF and IL-8 was highest on the periphery of a large tumor, where cell division is maximum. VEGF expression was higher in the center of the tumor. In vitro studies demonstrated that sparse cultures of tumor cells expressed higher levels of bFGF and IL-8 than confluent cultures. In contrast, the expression of bFGF and IL-8 was not diminished in tumor cells growing on confluent monolayers of normal cells. VEGF expression was upregulated by cell density irrespective of contact with tumor cells or normal cells. These results demonstrate that the expression of different angiogenic factors in tumor cells can be regulated by their proximity to other tumor cells or host cells.     

Molecular regulation of UVB-induced cutaneous angiogenesis

We determined whether cutaneous angiogenesis induced by exposure of mice to ultraviolet-B (UVB) radiation is associated with an imbalance between positive and negative angiogenesis-regulating molecules. Unshaved C3H/HeN mice were exposed to a single dose (15 kJ per m2) of UVB. At various times, the mice were killed, and their external ears were processed for routine histology and immunohistochemistry. Antibodies against proliferating cell nuclear antigen and bromodeoxyuridine identified dividing cells. Antibodies against CD31/ PECAM-1 identified endothelial cells, and antibodies against basic fibroblast growth factor (bFGF), vascular endothelial growth factor/vascular permeability factor, and interferon-beta (IFN-beta) identified angiogenesis-regulating molecules. Epidermal hyperplasia was documented by 48 h and reached a maximum on day 7 after exposure to UVB. The expression of bFGF increased by 24 h, whereas the expression of IFN-beta decreased by 72 h after exposure to UVB. The expression of vascular endothelial growth factor/vascular permeability factor increased slightly after irradiation. The altered balance between bFGF and IFN-beta was associated with increased endothelial cell proliferation (bromodeoxyuridine + CD31 + cells) within existing blood vessels, leading to telangiectasia and new blood vessels. UV-induced epidermal hyperplasia and cutaneous angiogenesis were highest in IFN-alpha/beta receptor knockout mice. These results demonstrate that in response to UVB radiation, dividing keratinocytes produce a positive angiogenic molecule (bFGF) but not a negative angiogenic molecule (IFN-beta), and that this altered balance is associated with enhanced cutaneous angiogenesis.     

Regulation of distinct steps of angiogenesis by different angiogenic molecules

This study was designed to determine the relative activity of basic fibroblast growth factor (bFGF), vascular endothelial growth factor/vascular permeability factor (VEGF/VPF), platelet-derived growth factor (PDGF), platelet-derived endothelial cell growth factor (PD-ECGF), hepatocyte growth factor (HGF), and interleukin-8 (IL-8) in regulating endothelial cell division, migration, degradation of the extracellular matrix (ECM), morphogenesis, and survival. Human umbilical vein endothelial cells (HUVEC) were treated with different concentrations of the six cytokines. bFGF was the most potent mitogen followed by VEGF/VPF and PD-ECGF. VEGF/VPF and bFGF also enhanced the survival of the endothelial cells in serum-free medium. Interstitial collagenase (MMP-1) and urokinase plasminogen activator (uPA) were significantly upregulated only by bFGF. HGF, bFGF, and VEGF/VPF induced chemotactic migration of the endothelial cells, but only HGF (scatter factor) enhanced nondirectional motility. The organization of endothelial cells to form tubes on Matrigel was induced by bFGF and, to a lesser extent, by VEGF/VPF and IL-8. Permeability across endothelial cell monolayers was induced only by VEGF/VPF. These data demonstrate that different angiogenic molecules differentially regulate distinct steps in the process of angiogenesis, suggesting that any given molecule may be necessary but in itself insufficient for establishment of a viable vasculature.     

Therapy of cancer metastasis by tumoricidal activation of tissue macrophages using liposome-encapsulated immunomodulators

Published results of hepatic cryotherapy are now available for almost 900 patients. Its safety is well established and its clinical role in treating patients with unresectable hepatoma or liver metastases from colorectal carcinoma is well supported by tumour marker and survival data; the results in the treatment of neuroendocrine liver metastases are promising. Its role as an alternative to liver resection is not yet well supported by long-term data. Although different adjuvant treatment protocols have been used following the cryotherapy of colorectal liver metastases, the effect of adjuvant treatment on recurrence or survival has not been assessed in prospective studies. Laparoscopic hepatic cryotherapy is feasible in selected patients with suitable tumour locations. However, the proportion of patients who might be usefully treated with this technique is not yet well established. The mechanisms of tissue destruction by freezing are reviewed.