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Purpose: In a significant nuclear event, hundreds of thousands of individuals will require rapid triage for absorbed radiation to ensure effective medical treatment and efficient use of medical res...

Purpose: There is a need to rapidly triage individuals for absorbed radiation dose following a significant nuclear event. Since most exposed individuals will not have physical dosimeters, we are de...

Purpose To identify a panel of radiation-responsive plasma proteins that could be used in a point-of-care biologic dosimeter to detect clinically significant levels of ionizing radiation exposure. Methods and Materials Patients undergoing preparation for hematopoietic cell transplantation using radiation therapy (RT) with either total lymphoid irradiation or fractionated total body irradiation were eligible. Plasma was examined from patients with potentially confounding conditions and from normal individuals. Each plasma sample was analyzed for a panel of 17 proteins before RT was begun and at several time points after RT exposure. Paired and unpaired t tests between the dose and control groups were performed. Conditional inference trees were constructed based on panels of proteins to compare the non-RT group with the RT group. Results A total of 151 patients (62 RT, 41 infection, 48 trauma) were enrolled on the study, and the plasma from an additional 24 healthy control individuals was analyzed. In comparison with to control individuals, tenascin-C was upregulated and clusterin was downregulated in patients receiving RT. Salivary amylase was strongly radiation responsive, with upregulation in total body irradiation patients and slight downregulation in total lymphoid irradiation patients compared with control individuals. A panel consisting of these 3 proteins accurately distinguished between irradiated patients and healthy control individuals within 3 days after exposure: 97% accuracy, 0.5% false negative rate, 2% false positive rate. The accuracy was diminished when patients with trauma, infection, or both were included (accuracy, 74%-84%; false positive rate, 14%-33%, false negative rate: 8%-40%). Conclusions A panel of 3 proteins accurately distinguishes unirradiated healthy donors from those exposed to RT (0.8-9.6 Gy) within 3 days of exposure. These findings have significant implications in terms of triaging individuals in the case of nuclear or other radiologic events.

Only a small fraction of short oligonucleotide probes bind efficiently to complementary segments in long RNA transcripts. Technologies such as array-based transcript profiling and antisense control of gene expression would benefit greatly from a method for predicting probes that bind well to a given target RNA. To develop an algorithm for prioritizing selection of probes, we have analyzed predicted thermodynamic parameters for the binding of several large sets of probes to complementary RNA transcripts. The binding of five of these sets of probes to their RNA targets has been reported by others. In addition, we have used a method for light-directed synthesis of oligonucleotide arrays that we developed to generate two new arrays of surface-bound probes and measured the binding of these probes to their RNA targets. We considered predicted free energies for intramolecular base pairing of the oligonucleotide and its RNA target as well as the predicted free energy of intermolecular hybridization of probe and target. We find that a reliable predictor of probes that will hybridize significantly with their targeted transcripts is the predicted free energy of hybridization minus the predicted free energy for intramolecular folding of the probe.

We have developed a method for the parallel analysis of multiple CpG sites in genomic DNA for their state of methylation. Hypermethylation of CpG islands within the promoters and 5′ exons of genes has been found to be a mechanism of transcriptional inactivation associated with a variety of tumors. The method that we developed relies on the differential reactivity of methylated and unmethylated cytosines with sodium bisulfite, which exclusively converts unmethylated cytosines to deoxyuracils. The resulting sequence changes are determined with single-nucleotide resolution by hybridization to an oligonucleotide array. Cohybridization with a reference sample containing a different label provides an internal standard for assessment of methylation state. This method provides advantages in parallelism over existing methods of methylation analysis. We have demonstrated this technique with a region from the promoter of the tumor suppressor gene p16, which is hypermethylated in many cancers.

I (IO) access is an old technique for gaining entrance to the systemic circulation, which has received a general resurgence in the last 30 years. IO access takes advantage of the vascularity of cancellous bone, the spongy bone inside the hard outer compact bone. Cancellous bone is composed of a lattice work of spicules or trabeculae and hematopoietic red marrow, creating a porous framework. Clinically relevant cancellous bone used for IO access is located at the ends of long bones, such as the humerus, femur, and tibia, and the sternum. Originally, IO access was recommended for use in the resuscitation of critically ill children with difficult intravenous (IV) access. Over time, the clinical use of IO access increased, and its status of use has been elevated by such prestigious organizations as theAmericanHeart Association Committee on Advanced Cardiac Life Support. IO access is now recommended as a rescue technique to treat all critically ill patients regardless of age, when peripheral IVaccess is difficult or impossible. Damage-control resuscitation (DCR) is the mainstay of modern combat resuscitation of the injured soldier and has been extended to civilian casualty care. DCR differs from previous resuscitation methods by emphasizing a bloodand coagulation factor resuscitation strategy. In this strategy, blood is preferred over crystalloid for volume replacement, and coagulation factor therapy is aggressively begun early in the resuscitation process to head off the lethal triad of coagulopathy, acidosis, and hypothermia. The rate-limiting step for rapid implementation of this transfusion strategy as part of DCR is satisfactory IV access. Standard advanced trauma life support (ATLS) guidelines emphasize the need for the rapid placement of multiple large bore peripheral IV catheters. When that placement is difficult or impossible, ATLS recommends the use of IO access for infusions of crystalloid or blood until alternative venous access is achieved. The recommendation of IO access for blood transfusion is found not only inATLSguidelines but also in recommendations from the Infusion Nurses Society (INS). In linewith these recommendations, IO access is used as a rescue access in the prehospital implementation of DCR in the combat setting. The scientific and clinical evidence for the use of IO access is voluminous, as evidenced by the Scientific Bibliography provided by VidaCare, one of the large manufacturers of IO devices, and available in any routine literature search. However, direct scientific and/or clinical data to support the use of IO access for the purpose of blood transfusion in adult humans are very limited to anecdotal reports. For example, in one case report on an injured soldier, six attempts were required to place four IO catheters that were reportedly used to transfuse 2 U of packed red blood cells (pRBCs). A civilian report of successful blood transfusion by the IO route in a 79-year-old female cannot be used to establish a foundation for the general use of the technique in the adult population since the nature of the bone varies greatly by age, sex, and ethnicity. In this era of evidence-based medicine, the absence of good evidence supporting the use of IO access for the very critical function of blood transfusion in DCR places existing recommendations for its use in question. This lack of evidence is compounded by the clinical experience of the lead author. Multiple attempts to use IO access for blood transfusion, both in the civilian adult emergency setting and in combat casualty care, have repeatedly been unsuccessful. These attempts were made by highly experienced clinicians using specificmanufacturers’ guidelines for IO infusion. In all cases, at best, flow rates totally insufficient for resuscitation with blood products were established. The procedureswere aborted because the pressure required to achieve even these rates exceeded the tolerance of the infusion system at its connections. This incongruity between field experience and existing recommendations by the leading authorities has initiated this review.

There has been increasing interest and efforts devoted to developing biosensor technologies for identifying pathogens, particularly in the biothreat area. In this study, a universal set of short 12- and 13-mer oligonucleotide probes was derived independently of a priori genomic sequence information and used to generate unique species-dependent genomic hybridization signatures. The probe set sequences were algorithmically generated to be maximally distant in sequence space and not dependent on the sequence of any particular genome. The probe set is universally applicable because it is unbiased and independent of hybridization predictions based upon simplified assumptions regarding probe-target duplex formation from linear sequence analysis. Tests were conducted on microarrays containing 14,283 unique probes synthesized using an in situ light-directed synthesis methodology. The genomic DNA hybridization intensity patterns reproducibly differentiated various organisms (Bacillus subtilis, Yersinia pestis, Streptococcus pneumonia, Bacillus anthracis, and Homo sapiens), including the correct identification of a blinded “unknown” sample. Applications of this method include not only pathological and forensic genome identification in medicine and basic science, but also potentially a novel method for the discovery of unknown targets and associations inherent in dynamic nucleic acid populations such as represented by differential gene expression.

A machine that employs a novel reagent delivery technique for biomolecular synthesis has been developed. This machine separates the addressing of individual synthesis sites from the actual process of reagent delivery by using masks placed over the sites. Because of this separation, this machine is both cost-effective and scalable, and thus the time required to synthesize 384 or 1536 unique biomolecules is very nearly the same. Importantly, the mask design allows scaling of the number of synthesis sites without the addition of new valving. Physical and biological comparisons between DNA made on a commercially available synthesizer and this unit show that it produces DNA of similar quality.

Given the enormous size of the genome and that there are potentially many other types of measurements we need to do to understand it, it has become necessary to pick and choose one's targets to measure because it is still impossible to evaluate the entire genome all at once. What has emerged is a need to have rapidly customizable microarrays. There are two dominant methods to accomplish custom microarray synthesis, Affymetrix-like microarrays manufactured using light projection rather than semiconductor-like masks used by Affymetrix to mass manufacture their GeneChip/sup TM/ arrays now, or the ink-jet printing method employed by Agilent. The manufacture of these custom Affymetrix-like microarrays can now be done on a digital optical chemistry (DOC) machine developed at the University of Texas Southwestern Medical Center, and this method offers much higher feature numbers and feature density than is possible with ink-jet printed arrays. On a microarray, each feature contains a single genetic measurement. The initial DOC prototype has been described in several publications, but that has now led to a second-generation machine. This machine reliably produces a number of arrays daily, has been deployed against a number of biomedical questions, is being used in new ways and has also led to a number of spin-off technologies.