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Biomedical subjects

Nicholas Dainiak

Publications and source records attributed to Nicholas Dainiak.

8 recordsLinked to original sources
PubMed2006

Development of a statewide hospital plan for radiologic emergencies.

Although general guidelines have been developed for triage of victims in the field and for hospitals to plan for a radiologic event, specific information for clinicians and administrators is not available for guidance in efficient management of radiation victims during their early encounter in the hospital. A consensus document was developed by staff members of four Connecticut hospitals, two institutions of higher learning, and the State of Connecticut Department of Environmental Protection and Office of Emergency Preparedness, with assistance of the American Society for Therapeutic Radiology and Oncology. The objective was to write a practical manual for clinicians (including radiation oncologists, emergency room physicians, and nursing staff), hospital administrators, radiation safety officers, and other individuals knowledgeable in radiation monitoring that would be useful for evaluation and management of radiation injury. The rationale for and process by which the radiation response plan was developed and implemented in the State of Connecticut are reviewed. Hospital admission pathways are described, based on classification of victims as exposed, contaminated, and/or physically injured. This manual will be of value to those involved in planning the health care response to a radiologic event.

Connecticut↗
PubMed2006

Acute radiation injury: contingency planning for triage, supportive care, and transplantation.

Evaluation and management of victims of exposure to myelosuppressive radiation in a military, terrorist, or accidental event is challenging. The hematopoietic syndrome with marrow suppression and pancytopenia follows intermediate intensity radiation exposure and as such produces a clinical syndrome similar to that after myelosuppressive chemotherapy or stem cell transplantation. Therefore, hematologists, oncologists, and transplantation physicians have the opportunity and challenge to plan for care of irradiation victims. Management of the hematopoietic syndrome, as a component of acute radiation sickness, requires understanding its manifestations and implementation of clinical biodosimetry to provide appropriate therapeutic support. Hematopoietic growth factors may be of value if administered early as a component of supportive care. Planning for urgent stem cell transplantation for those with intermediate- to high-dose radiation (4-10 Gy) may be required. Establishing contingency plans for triage, assessment, supportive care, and treatment resembles the development of phase II trials, with defined eligibilities, treatment plans, and incorporated data collection to assess results and plan further improvements in care. The hematology/oncology community is most suited to participate in such contingency planning, and the necessary elements for its success are reviewed.

Anemia, Aplastic↗
PubMed2004

Medical management of the acute radiation syndrome: recommendations of the Strategic National Stockpile Radiation Working Group.

Physicians, hospitals, and other health care facilities will assume the responsibility for aiding individuals injured by a terrorist act involving radioactive material. Scenarios have been developed for such acts that include a range of exposures resulting in few to many casualties. This consensus document was developed by the Strategic National Stockpile Radiation Working Group to provide a framework for physicians in internal medicine and the medical subspecialties to evaluate and manage large-scale radiation injuries. Individual radiation dose is assessed by determining the time to onset and severity of nausea and vomiting, decline in absolute lymphocyte count over several hours or days after exposure, and appearance of chromosome aberrations (including dicentrics and ring forms) in peripheral blood lymphocytes. Documentation of clinical signs and symptoms (affecting the hematopoietic, gastrointestinal, cerebrovascular, and cutaneous systems) over time is essential for triage of victims, selection of therapy, and assignment of prognosis. Recommendations based on radiation dose and physiologic response are made for treatment of the hematopoietic syndrome. Therapy includes treatment with hematopoietic cytokines; blood transfusion; and, in selected cases, stem-cell transplantation. Additional medical management based on the evolution of clinical signs and symptoms includes the use of antimicrobial agents (quinolones, antiviral therapy, and antifungal agents), antiemetic agents, and analgesic agents. Because of the strong psychological impact of a possible radiation exposure, psychosocial support will be required for those exposed, regardless of the dose, as well as for family and friends. Treatment of pregnant women must account for risk to the fetus. For terrorist or accidental events involving exposure to radioiodines, prophylaxis against malignant disease of the thyroid is also recommended, particularly for children and adolescents.

Animals↗
PubMed2003

Modulation of intercellular communication mediated at the cell surface and on extracellular, plasma membrane-derived vesicles by ionizing radiation.

The plasma membrane is a dynamic organelle whose function includes receptor-mediated signal transduction into the cell. Conversely, the plasma membrane is the origin of inter-cellular signaling. In addition to expressing and releasing growth factors in a soluble form(through exocytosis) and via proteolysis of cell surface components, membrane ligands may signal nearby cells through juxtacrine stimulation or by the exfoliation or shedding of plasma membrane-derived vesicles. Ionizing radiation (IR) has a profound effect on plasma membrane structure and function. IR-induced ultrastructural alterations are mediated via lipid interaction with water radiolysis products (e.g., hydroxyl radicals, hydrogen radicals, and hydrated electrons). Ionizing radicals act directly on lipid molecules to promote lipid hydro-peroxides and lipid hydroperoxide breakdown products (e.g., alpha, beta unsaturated aldehydes) that contribute to altered plasma membrane lipid composition. A change in lipid composition increases membrane lipid microviscosity and results in membrane fenestrations that enhance permeability to small molecules and ions. Reactive ionizing species also stimulate sphingomyelinase activity, leading to sphingomyelin hydrolysis and ceramide generation that further contributes to altered membrane lipid composition and cellular apoptosis. In addition, exposure to IR results in impaired rate of and cumulative shedding of plasma membrane-associated growth factors. Mechanisms of exfoliation are reviewed for normal cells and the impact of radiation on modulating signal transduction mediated by exfoliation is summarized.

Apoptosis↗
PubMed2003

The hematologist and radiation casualties.

Since the terrorist attack of September 11, 2001, preparation by the health care system for an act of terrorism has been mandated by leaders of governments. Scenarios for terrorist acts involving radioactive material have been identified, and approaches to management (based on past experience from atomic weapons detonations and radiation accidents) have been developed. Because of their experience in managing patients with profound cytopenia and/or marrow aplasia, hematologists will be asked to play a significant role in evaluating and treating victims of mass accidental or deliberate exposure to radiation. This review provides a framework for understanding how radiation levels are quantified, how radiation alters the function of hematopoietic (and nonhematopoietic) cells and tissues, and how victims receiving a significant radiation dose can be identified and managed. In Section I, Dr. Nicholas Dainiak reviews four components of the Acute Radiation Syndrome: the hematopoietic, neurovascular, gastrointestinal and cutaneous subsyndromes. Clinical signs and symptoms are discussed for exposed individuals at the time of initial presentation (the prodromal phase) and during their course of disease (the manifest illness). In Section II, he presents clinical and laboratory methods to assess radiation doses, including time to onset and severity of vomiting, rate of decline in absolute blood lymphocyte count and the appearance of chromosome aberrations such as dicentrics and ring forms. Potential scenarios of a radiation terrorist event are reviewed, and methods for initial clinical assessment, triage, and early management of the acute radiation syndrome and its component subsyndromes are summarized. In Section III, Dr. Jamie Waselenko reviews the hematopoietic syndrome, and presents guidelines for the use of cytokine therapy, antibiotics, and supportive care that have been developed by the Strategic National Pharmaceutical Stockpile Working Group. Results of preclinical and clinical growth factor therapy studies with G-CSF, GM-CSF, pegylated G-CSF, SCF, and IL-3 are summarized. When and how potassium iodide should be used after exposure to radioiodines is also reviewed. In Section IV, Dr. James Armitage describes a narrow "window" of 7 to 10 Gy where therapy with stem cell transplantation may be appropriate. Victims who are candidates for allotransplantation should not have major trauma or significant injury to other (nonhematopoietic) tissues. Rarely, victims may have an identical sibling or autologous stored marrow or blood stem cells, in which case the threshold for transplantation is 4 Gy. In Section V, Dr. Thomas MacVittie describes new directions for therapy, using cytokines such as IL-7, keratinocyte growth factor, and FLT-3. The potential for combinations of cytokines to enhance hematopoietic recovery is also reviewed.

Anti-Bacterial Agents↗
PubMed2002

Hematologic consequences of exposure to ionizing radiation.

From the early 1900s, it has been known that ionizing radiation (IR) impairs hematopoiesis through a variety of mechanisms. IR exposure directly damages hematopoietic stem cells and alters the capacity of bone marrow stromal elements to support and/or maintain hematopoiesis in vivo and in vitro. Exposure to IR induces dose-dependent declines in circulating hematopoietic cells not only through reduced bone marrow production, but also by redistribution and apoptosis of mature formed elements of the blood. Recently, the importance of using lymphocyte depletion kinetics to provide a "crude" dose estimate has been emphasized, particularly in rapid assessment of large numbers of individuals who may be exposed to IR through acts of terrorism or by accident. A practical strategy to estimate radiation dose and triage victims based upon clinical symptomatology is presented. An explosion of knowledge has occurred regarding molecular and cellular pathways that trigger and mediate hematologic responses to IR. In addition to damaging DNA, IR alters gene expression and transcription, and interferes with intracellular and intercellular signaling pathways. The clinical expression of these disturbances may be the development of leukemia, the most significant hematologic complication of IR exposure among survivors of the atomic bomb detonations over Japan. Those at greatest risk for leukemia are individuals exposed during childhood. The association of leukemia with chronic, low-dose-rate exposure from nuclear power plant accidents and/or nuclear device testing has been more difficult to establish, due in part to lack of precision and sensitivity of methods to assess doses that approach background radiation dose. Nevertheless, multiple myeloma may be associated with chronic exposure, particularly in those exposed at older ages.

Cell Survival↗
PubMedDate not supplied

Recommended modifications and applications of the Hospital Emergency Incident Command System for hospital emergency management.

The Hospital Emergency Incident Command System (HEICS), now in its third edition, has emerged as a popular incident command system model for hospital emergency response in the United States and other countries. Since the inception of the HEICS in 1991, several events have transformed the requirements of hospital emergency management, including the 1995 Tokyo Subway sarin attack, the 2001 US anthrax letter attacks, and the 2003 Severe Acute Respiratory Syndrome (SARS) outbreaks in eastern Asia and Toronto, Canada. Several modifications of the HEICS are suggested to match the needs of hospital emergency management today, including: (1) an Incident Consultant in the Administrative Section of the HEICS to provide expert advice directly to the Incident Commander in chemical, biological, radiological, nuclear (CBRN) emergencies as needed, as well as consultation on mental health needs; (2) new unit leaders in the Operations Section to coordinate the management of contaminated or infectious patients in CBRN emergencies; (3) new unit leaders in the Operations Section to coordinate mental health support for patients, guests, healthcare workers, volunteers, and dependents in terrorism-related emergencies or events that produce significant mental health needs; (4) a new Decedent/Expectant Unit Leader in the Operations Section to coordinate the management of both types of patients together; and (5) a new Information Technology Unit Leader in the Logistics Section to coordinate the management of information technology and systems. New uses of the HEICS in hospital emergency management also are recommended, including: (1) the adoption of the HEICS as the conceptual framework for organizing all phases of hospital emergency management, including mitigation, preparedness, response, and recovery; and (2) the application of the HEICS not only to healthcare facilities, but also to healthcare systems. Finally, three levels of healthcare worker competencies in the HEICS are suggested: (1) basic understanding of the HEICS for all hospital healthcare workers; (2) advanced understanding and proficiency in the HEICS for hospital healthcare workers likely to assume leadership roles in hospital emergency response; and (3) special proficiency in constituting the HEICS ad hoc from existing healthcare workers in resource-deficient settings. The HEICS should be viewed as a work in progress that will mature as additional challenges arise and as hospitals gain further experience with its use.

Emergency Medical Service Communication Systems↗