Anticoagulation: assessment of benefits and risks

Thromboembolism is a frequent complication of atrial fibrillation. As could be demonstrated by several placebo-controlled prospective studies in the recent years the rate of thromboembolism was reduced significantly by anticoagulation of nearly all kinds of atrial fibrillation. These results are challenging to weigh risks and benefits in every patient. The principles which have to consider in this calculation are discussed with regard to the knowledge derived from the controlled studies.     

The decline in serum albumin after conversion to high flux, high efficiency dialysis

In previous works using cytofluorometry, we demonstrated a broad range of IgE and IgE-receptor levels within individual mast cell populations with a 60 to 80% occupancy of the IgE receptors on mast cells by native IgE. This study was performed in order to confirm our previous findings using an independent method and to visualize the distribution of IgE-receptor complexes on mast cells at an ultrastructural level. For this purpose an indirect immunocolloidal gold-labelling technique has been applied. By counting the number of labelled gold particles, a relative measure of IgE-receptor surface expression and IgE occupancy of the receptors could be obtained. With respect to mast cell morphology and anti-IgE binding specificity criteria, 1% glutaraldehyde + 4% paraformaldehyde (1:1, vol/vol) was found to be the best of the seven fixatives applied in this study. This technique revealed numerous gold particles on the surface of mast cells from barrier-maintained rats (26 +/- 11 per mast cell section, mean +/- SD). Increased numbers of gold particles were counted if the mast cells were incubated with rat myeloma IgE (20 micrograms/ml) (46 +/- 33 per mast cell section, mean +/- SD). There were significantly increased numbers of gold particles on the mast cells of rats infected with N. brasiliensis (126 +/- 30 per mast cell section, mean +/- SD). This indicates that some of the IgE receptors (about 50% of the total number of IgE receptors in this case) on mast cells were occupied by native IgE and that parasite infection significantly increased the number of IgE molecules on the surface of the mast cells. These results correspond with the findings we have made using the cytofluorometric technique and confirm the large individual variations in the density of IgE receptors and IgE among the mast cells of a given cell population. Macrophages, lymphocytes and eosinophils, carrying the low-affinity IgE receptors (Fc epsilon RII), contained less than 5 (normal rats after incubation in rat IgE) or 10 (nematode-infected rats) gold particles per cell section. We also observed some non-granulated lymphocyte-like cells which bound a large number of gold particles after incubation with rat myeloma IgE (20 micrograms/ml), indicating that they contained IgE receptors Fc epsilon RI). They were interpreted as mast cell precursors which have previously been shown to exist in the peritoneal cavity.     

Nanotechnology: Scientific challenges and societal benefits and risks

The field of nanotechnology is developing rapidly, as are its practical application in society. In this article, we give examples that demonstrate the enormous potential that exists for this new class of materials, and for devices with critical dimensions of less than 100 nm. We also identify some of the challenges that need to be faced in order to fully realize the practical benefits of nanotechnology, and discuss possible risks that may come with this new technology. In all cases, the unique advantage of nanotechnology can be traced back to nanoscale physical and chemical properties that are quite different from those encountered in more traditional microscopic (micro) or macroscopic (macro) materials and devices. Unique nanoscale properties and behaviors are already being used to increase energy efficiency, improve healthcare, and strengthen national security. However, while progress is rapid, many challenges remain. These include manufacturing at the nanoscale, integration of nanoscale materials and devices with more conventional technology, and predictive modeling that will allow nanotechnology to be engineered reliably into useful applications and products. Nanotechnology can be expected to have an increasing impact on human lives and society at large. As we strive to use nanotechnology to improve human life through better healthcare, cleaner environment, and improved national security, we must also work to detect and assess the negative impacts that nanotechnology science (or any new technology) might bring. We suggest that the conduct of should be allowed to proceed unimpeded, so that we can fully understand and appreciate the rules of nature at the nanometer scale. That said, scientific pursuits that involve self-replication in synthetic systems, encryption, defense technology, or the enhancement of human intelligence should be reviewed. The development of new technology from fundamental science and the process of deciding what new technology is to be created for what purpose are topics for reasoned debate among the general public as well as in the forums of scientific peer review and political decision making. Dr. Alton D. Romig, Jr., is currently Vice President, Nonproliferation and Assessments, at Sandia National Laboratories (Albuquerque, NM). His responsibilities include the leadership and management of the development and engineering activities that provide systems, science, technology, and expertise in support of national objectives to reduce the threat to the United States from proliferation of and use of weapons of mass destruction. Program areas include remote sensing, proliferation assessment, technology assessment, international security, physical security, and nuclear/chemical/biological nonproliferation and counterintelligence. Dr. Romig is a member of the National Academy of Engineering and is active on a number of National Academy of Engineering/National Research Council Committees and Boards. He is a Fellow of the American Association for the Advancement of Science (AAAS) and member of Science, Engineering and Public Policy Committee and TMS (Fellow Class of 2005) (The Metals, Minerals and Materials Society). Dr. Romig is also Fellow and former President of ASM INTERNATIONAL (formerly American Society for Metals). He also serves on the Boards of Atomic Weapons Establishment Management Limited, a Lockheed Martin joint venture company in the United Kingdom, and Technology Ventures Corporation, a Lockheed Martin subsidiary dedicated to technology commercialization. For his pioneering work in analytical electron microscopy and solidstate diffusion, Dr. Roming has received several awards, including the Burton Medal (1988), awarded by the Electron Microscopy Society of America to an Outstanding Young Scientist; the K.F.J. Heinrich Award (1991), given by the Microbeam Analysis Society to an Outstanding Young Scientist; the ASM Silver Medal for Outstanding Materials Research (1992); and the Acta Metallurgica International Lectureship (1993–1994). Dr Roming has also been named the 2003 ASM-TMS Distinguished Lecturer in Materials and Society. He received his B.S., M.S., and Ph.D. degrees in materials science and engineering from Lehigh University in 1975, 1977, and 1979, respectively. In 1979, he joined Sandia National Laboratories as a member of the technical staff, Physical Metallurgy Division. After a variety of management assignments, he was named Director, Materials and Process Sciences, in 1992. From 1995 to 1999, he was Director of Microsystems Science, Technology, and Components. In 1999, he was named Chief Technology Officer and Vice President for Science, Technology, and Partnerships. In that role, he was Chief Scientific Officer for the Nuclear Weapons program, accountable for Sandia’s interactions with industry and the Laboratories’ Campus Executive program. In addition, he was responsible for the Laboratory Directed Research & Development program. He served in this capacity until attaining his present position in 2003. With Terry A. Michalske and R.J. Floran     

Nanotechnology: Scientific challenges and societal benefits and risks

The field of nanotechnology is developing rapidly, as are its practical application in society. In this article, we give examples that demonstrate the enormous potential that exists for this new class of materials, and for devices with critical dimensions of less than 100 nm. We also identify some of the challenges that need to be faced in order to fully realize the practical benefits of nanotechnology, and discuss possible risks that may come with this new technology. In all cases, the unique advantage of nanotechnology can be traced back to nanoscale physical and chemical properties that are quite different from those encountered in more traditional microscopic (micro) or macroscopic (macro) materials and devices. Unique nanoscale properties and behaviors are already being used to increase energy efficiency, improve healthcare, and strengthen national security. However, while progress is rapid, many challenges remain. These include manufacturing at the nanoscale, integration of nanoscale materials and devices with more conventional technology, and predictive modeling that will allow nanotechnology to be engineered reliably into useful applications and products. Nanotechnology can be expected to have an increasing impact on human lives and society at large. As we strive to use nanotechnology to improve human life through better healthcare, cleaner environment, and improved national security, we must also work to detect and assess the negative impacts that nanotechnology (or any new technology) might bring. We suggest that the conduct of science should be allowed to proceed unimpeded, so that we can fully understand and appreciate the rules of nature at the nanometer scale. That said, scientific pursuits that involve self-replication in synthetic systems, encryption, defense technology, or the enhancement of human intelligence should be reviewed. The development of new technology from fundamental science and the process of deciding what new technology is to be created for what purpose are topics for reasoned debate among the general public as well as in the forums of scientific peer review and political decision making. Dr. Alton D. Romig, Jr., is currently Vice President, Nonproliferation and Assessments, at Sandia National Laboratories (Albuquerque, NM). His responsibilities include the leadership and management of the development and engineering activities that provide systems, science, technology, and expertise in support of national objectives to reduce the threat to the United States from proliferation of and use of weapons of mass destruction. Program areas include remote sensing, proliferation assessment, technology assessment, international security, physical security, and nuclear/chemical/biological nonproliferation and counterintelligence. Dr. Romig is a member of the National Academy of Engineering and is active on a number of National Academy of Engineering/National Research Council Committees and Boards. He is a Fellow of the American Association for the Advancement of Science (AAAS) and member of Science, Engineering and Public Policy Committee and TMS (Fellow Class of 2005) (The Metals, Minerals and Materials Society). Dr. Romig is also Fellow and former President of ASM INTERNATIONAL (formerly American Society for Metals). He also serves on the Boards of Atomic Weapons Establishment Management Limited, a Lockheed Martin joint venture company in the United Kingdom, and Technology Ventures Corporation, a Lockheed Martin subsidiary dedicated to technology commercialization. For his pioneering work in analytical electron microscopy and solid-state diffusion, Dr. Romig has received several awards, including the Burton Medal (1988), awarded by the Electron Microscopy Society of America to an Outstanding Young Scientist; the K.F.J. Heinrich Award (1991), given by the Microbeam Analysis Society to an Outstanding Young Scientist; the ASM Silver Medal for Outstanding Materials Research (1992); and the Acta Metallurgica International Lectureship (1993–1994). Dr. Romig has also been named the 2003 ASM-TMS Distinguished Lecturer in Materials and Society. He received his B.S., M.S., and Ph.D. degrees in materials science and engineering from Lehigh University in 1975, 1977, and 1979, respectively. In 1979, he joined Sandia National Laboratories as a member of the technical staff, Physical Metallurgy Division. After a variety of management assignments, he was named Director, Materials and Process Sciences, in 1992. From 1995 to 1999, he was Director of Microsystems Science, Technology, and Components. In 1999, he was named Chief Technology Officer and Vice President for Science, Technology, and Partnerships. In that role, he was Chief Scientific Officer for the Nuclear Weapons program, accountable for Sandia’s interactions with industry and the Laboratories’ Campus Executive program. In addition, he was responsible for the Laboratory Directed Research & Development program. He served in this capacity until attaining his present position in 2003. With Terry A. Michalske and R.J. Floran     

Snake and spider antivenin: risks and benefits of therapy

A case of hepatic mesenchymal hamartoma, found after sudden onset clinical and biological cholestasis, is reported in a 18-year-old man. Abdominal ultrasound examination and computed tomography showed a intrahepatic cystic tumor. The diagnosis of hepatic mesenchymal hamartoma was made by the pathological examination of the resected specimen. This rare tumor is found in most cases in children less than 2 years old. Thirteen cases in adulthood were already reported, five of them in Japanese patients. Our case is peculiar because no hepatic tumor was shown by ultrasound examination, 2 years before, the large size of cysts and presence of smooth muscle fibers in the wall.     

Continuous "high flux" dialysis: an effective renal replacement therapy for intensive care patients

Currently available replacement therapies for the treatment of acute renal failure are reviewed. Particular interest is focused on their application in intensive care, especially in septic patients. Underlying principles and mechanisms of action are explained. The continuous "High flux-dialysis" is shown to be a particularly effective form of renal replacement therapy.     

The problems of radon therapy: its benefits and risks]

Local administration of drugs by means of aerosol device is widely used in the treatment of asthma. Nevertheless, the effectiveness of this method depends on an adequate inhalation technique (IT), which available evidence has shown to be rather problematic. The aim of this study was to assess IT in out-patients with bronchial asthma who frequently use aerosol therapy with Pressurized Metered dose inhalers (MDI), pressurized inhalers with spacer (MDI-S) and the Astra-Draco Turbuhaler system (TH). A sample of 150 adults with asthma were evaluated. These patients had been followed up for than two years and they often used one of the devices mentioned above. The IT has broken down into several steps for each procedure. Percentages of patients with one error in the IT were 50%, 44% and 42% for MDI, MDI-S and TH procedures, respectively. 18%, 20% and 14% of patients committed three errors in the IT, respectively. Differences detected were not significant. Seven patients committed errors in every step of the IT. In conclusion, the level of errors found in our study is high, similar to that cited in the existing literature. It is also roughly equivalent for the three devices tested. We believe that the proper teaching monitoring of IT skills is highly important in the treatment of bronchial asthma.     

Interleukin-10: potential benefits and possible risks in clinical infectious diseases

Human interleukin-10 (IL-10) is a potent anti-inflammatory cytokine that inhibits the synthesis of the major proinflammatory cytokines and chemokines. IL-10 is the principal TH2-type cytokine that upregulates humoral immune responses and attenuates cell-mediated immune reactions. This cytokine has a number of immunomodulatory properties that might be clinically useful in a variety of inflammatory and infectious disease states. Clinical trials with human recombinant IL-10 are already in progress. Carefully selected patients with inflammatory conditions may benefit from IL-10 therapy if concomitant infectious diseases are recognized and treated appropriately.     

Pretreatment evaluation of chronic hepatitis C: risks, benefits, and costs

CONTEXT: Chronic hepatitis C (CHC) infection affects nearly 4 million people in the United States. Treatment with interferon alfa-2b has been limited by its cost and low likelihood of long-term response. OBJECTIVE: To examine the cost-effectiveness of alternative pretreatment management strategies for patients with CHC. DESIGN: Decision and cost-effectiveness analysis using a Markov model to examine prevalence of genotypes, viral load, and histological characteristics in relation to the sustained response rate with treatment. Data were based on a previously published decision model and a MEDLINE literature search for hepatitis C, biopsy, and liver from 1966 to 1996. PATIENTS: A hypothetical population of patients with CHC infection and elevated serum alanine aminotransferase level. INTERVENTIONS: Combinations of liver biopsy, genotyping, and quantitative viral load determination prior to a single 6-month course of interferon alfa-2b; empirical interferon treatment; and conservative management. MAIN OUTCOME MEASURES: Proportion of sustained responders, lifetime costs, life expectancy, and quality-adjusted life expectancy. RESULTS: Strategies involving hepatitis C virus (HCV) RNA testing had marginal cost-effectiveness ratios up to $4400 per discounted quality-adjusted life-year gained but would miss up to 36% of sustained responders. Empirical interferon treatment had a marginal cost-effectiveness ratio of $12400 per discounted quality-adjusted life-year gained and reached all potential sustained responders. Strategies involving liver biopsy were more expensive and would miss 6% of sustained responders and yield slightly lower life expectancies. CONCLUSIONS: Routine liver biopsy before treatment with interferon increases the cost of managing patients with CHC without improving health outcomes. Using quantitative HCV RNA testing to guide therapy misses some potential sustained responders. Empirical interferon treatment has a marginal cost-effectiveness ratio within the bounds of other commonly accepted therapies and misses none of the sustained responders.     

Weighing the risks and benefits of an oral cancer screening

The study into the causes underlying nonspecific lymphadenitis (NSL) and adenophlegmons of the maxillofacial region and the neck (AF) revealed a great variety of etiological factors and primary infectious foci in these diseases. Of 204 children admitted to hospital of the city of Derbent, odontogenic genesis of the disease was determined in 27.45% of cases; dermatogenic, stomatogenic in 23.04 and 12.74% of cases, respectively. ENT and systemic diseases were responsible for NSL and AF in 13.23 and 3.43% of cases. The cause remained unclear in 20.09% of patients. NSL and AF occurred most frequently in the coldest (January, February) and the hottest (July, August) months of the year.     

The benefits and risks of n-3 polyunsaturated fatty acids

There is a growing number of animal models and clinical trials of n-3 polyunsaturated fatty acid (PUFAs) supplementation in disease. Epidemiologic and biochemical studies have suggested beneficial effects of n-3 PUFAs. But also, the use of n-3 PUFAs has some potential toxicological risks that can be circumvented by careless processing, storing, and preserving the PUFAs. The use of n-3 PUFAs is safe if appropriate preparations and dosages are selected. Much research is needed to clarify their use under different disease conditions. The newly established clinical and nutritional facts on n-3 PUFAs will induce industry to develop food products based on this knowledge.