Heterophilic interference in specimens yielding false-reactive results on the Abbott 4th generation ARCHITECT HIV Ag/Ab Combo assay.

BACKGROUND: False-reactivity in HIV-negative specimens has been detected in HIV fourth-generation antigen/antibody or 'combo' assays which are able to detect both anti-HIV-1/HIV-2 antibodies and HIV-1 antigen. OBJECTIVES: We sought to characterize these specimens and determine the effect of heterophilic interference. STUDY DESIGN: Specimens previously testing as false-reactive on the Abbott ARCHITECT HIV Ag/Ab combo assay and re-tested on a different (Siemens ADVIA Centaur HIV Ag/Ab) assay. A subset of these specimens were also pre-treated with heterophilic blocking agents and re-tested on the Abbott assay. RESULTS: Here we report that 95% (252/264) of clinical specimens that were repeatedly reactive on the Abbott ARCHITECT HIV Ag/Ab combo assay (S/Co range, 0.94-678) were negative when re-tested on a different fourth generation HIV combo assay (Siemens ADVIA Centaur HIV Ag/Ab). All 264 samples were subsequently confirmed to be HIV negative. On a small subset (57) of specimens with available volume, pre-treatment with two different reagents (HBT; Heterophilic Blocking Tube, NABT; Non-Specific Blocking Tube) designed to block heterophilic antibody interference either eliminated (HBT) or reduced (NABT) the false reactivity when re-tested on the ARCHITECT HIV Ag/Ab combo assay. CONCLUSIONS: Our results suggest that the Abbott ARCHITECT HIV Ag/Ab combo assay can be prone to heterophilic antibody interference.

Upregulation of the microRNA cluster at the Dlk1-Dio3 locus in lung adenocarcinoma.

Mice in which lung epithelial cells can be induced to express an oncogenic Kras(G12D) develop lung adenocarcinomas in a manner analogous to humans. A myriad of genetic changes accompany lung adenocarcinomas, many of which are poorly understood. To get a comprehensive understanding of both the transcriptional and post-transcriptional changes that accompany lung adenocarcinomas, we took an omics approach in profiling both the coding genes and the non-coding small RNAs in an induced mouse model of lung adenocarcinoma. RNAseq transcriptome analysis of Kras(G12D) tumors from F1 hybrid mice revealed features specific to tumor samples. This includes the repression of a network of GTPase-related genes (Prkg1, Gnao1 and Rgs9) in tumor samples and an enrichment of Apobec1-mediated cytosine to uridine RNA editing. Furthermore, analysis of known single-nucleotide polymorphisms revealed not only a change in expression of Cd22 but also that its expression became allele specific in tumors. The most salient finding, however, came from small RNA sequencing of the tumor samples, which revealed that a cluster of ∼53 microRNAs and mRNAs at the Dlk1-Dio3 locus on mouse chromosome 12qF1 was markedly and consistently increased in tumors. Activation of this locus occurred specifically in sorted tumor-originating cancer cells. Interestingly, the 12qF1 RNAs were repressed in cultured Kras(G12D) tumor cells but reactivated when transplanted in vivo. These microRNAs have been implicated in stem cell pleuripotency and proteins targeted by these microRNAs are involved in key pathways in cancer as well as embryogenesis. Taken together, our results strongly imply that these microRNAs represent key targets in unraveling the mechanism of lung oncogenesis.

Survey of influenza A viruses circulating in wild birds in Canada 2005 to 2007.

A multi-agency, Canada-wide survey of influenza A viruses circulating in wild birds, coordinated by the Canadian Cooperative Wildlife Health Centre, was begun in the summer of 2005. Cloacal swab specimens collected from young-of-year ducks were screened for the presence of influenza A nucleic acids by quantitative, real-time reverse transcription-polymerase chain reaction (RRT-PCR). Specimens that produced positive results underwent further testing for H5 and H7 gene sequences and virus isolation. In addition to live bird sampling, dead bird surveillance based on RRT-PCR was also carried out in 2006 and 2007. The prevalence of influenza A viruses varied depending on species, region of the country, and the year of sampling, but generally ranged from 20% to 50%. All HA subtypes, with the exception of H14 and H15, and all NA subtypes were identified. The three most common HA subtypes were H3, H4, and H5, while N2, N6, and N8 were the three most common NA subtypes. H4N6, H3N2, and H3N8 were the three most common HA-NA combinations. The prevalence of H5 and H7 subtype viruses appears to have a cyclical nature.

Safety and efficacy of early surgical decompression of the thoracic outlet for Paget-Schroetter syndrome.

The surgical treatment of Paget-Schroetter syndrome has evolved to include early thrombolytic therapy and an interval period of anticoagulation, followed by late surgical decompression of the thoracic outlet. More recently, we have developed an abbreviated course of therapy in which the thrombolytic therapy is followed by early surgical decompression during the same admission, then a period of anticoagulation. We compared early surgical decompression with the standard management protocol to determine safety and efficacy of the early treatment algorithm. Nine patients were treated with lysis and early operation. These were compared with the preceding nine consecutive patients treated with lysis and staged operation. Demographic data, risk factors, duration of thrombosis, lytic therapy, time to surgery, operative variables, and postoperative complications were analyzed. Our results showed that thrombolysis followed by early operation does not result in increased perioperative morbidity or mortality. Early surgical decompression of the thoracic outlet during the same admission as lysis is as safe and efficacious as the traditional (staged decompression) approach to Paget-Schroetter syndrome. Lysis followed by early surgical decompression should be considered a new standard of care in the management of Paget-Schroetter syndrome.

Endovascular, transperitoneal, and retroperitoneal abdominal aortic aneurysm repair: results and costs.

PURPOSE: Contemporary treatment of abdominal aortic aneurysms (AAA) includes transabdominal (TA), retroperitoneal (RP), and endovascular (EV) repair. This study compares the cost and early (30-day) results of a consecutive series of AAA repair by means of these three methods in a single institution. METHODS: A total of 125 consecutive AAA repairs between February 1993 and August 1997 were reviewed. Risk factors, 30-day morbidity and mortality rates, and hospital stay and cost were analyzed according to method of repair (TA, RP, EV). Cost was normalized by means of a conversion factor to maintain confidentiality. Cost analysis includes conversion to TA repair (intent to treat) in the EV group. RESULTS: One hundred twenty-five AAA repairs were performed with the TA (n = 40), RP (n = 24), or EV (n = 61) approach. Risk factors among the groups (age, coronary artery disease, hypertension, diabetes, chronic obstructive pulmonary disease, and cigarette smoking) were not statistically different, and thus the groups were comparable. The average estimated blood loss was significantly lower for EV (300 mL) than for RP (700 mL) and TA (786 mL; P>.05). Statistically significant higher cost for TA and RP for pharmacy and clinical laboratories (likely related to increased length of stay [LOS]) and significantly higher cost for EV in supplies and radiology (significantly reducing cost savings in LOS) were revealed by means of an itemized cost analysis. Operating room cost was similar for EV, TA, and RP. There were six perigraft leaks (9.6%) and six conversions to TA (9.6%) in the EV group. CONCLUSION: There were no statistically significant differences in mortality rates among TA, RP, and EV. Respiratory failure was significantly more common after TA repair, compared with RP or EV, whereas wound complications were more common after RP. Overall cost was significantly higher for TA repair, with no significant difference in cost between EV and RP. EV repair significantly shortened hospital stay and intensive care unit (ICU) use and had a lower morbidity rate. Cost savings in LOS were significantly reduced in the EV group by the increased cost of supplies and radiology, accounting for a similar cost between EV and RP. Considering the increased resource use preoperatively and during follow-up for EV patients, the difference in cost between TA and EV may be insignificant. EV repair is unlikely to save money for the health care system; its use is likely to be driven by patient and physician preference, in view of a significant decrease in the morbidity rate and length of hospital stay.

Improving pain management in critical care.

BACKGROUND: In April 1994 at the University of California at Los Angeles Medical Center the Surgical Intensive Care Unit's (SICU's) Quality Improvement Council unanimously agreed on pain management as one of the major factors that negatively affect outcomes for their patient population. Using the FOCUS-PDCA (plan-do-check-act) model for quality improvement (QI), the council chartered a subcommittee to improve the pain management in their ICUs. METHODOLOGY: The subcommittee first measured the pain assessment scores of patients at transfer from the ICU. After ascertaining that these scores were greater than the goal of 2, the process of providing pain relief was examined with the assistance of process control statistics, which showed a process barely capable of meeting the goal of pain score of 2 or less on a 0-5 scale. The process factors that affected this outcome were examined and changes were made where appropriate. One of these changes was development of a guideline for acute pain management based on the Agency for Health Care Policy Research's Acute Pain Management Clinical Practice Guideline. Reassessment of the pain scores and the process was then conducted. RESULTS: The pain assessment scores at transfer from the ICU decreased significantly. Thirty-five percent of patients in the preguideline survey rated their scores as greater than 2, compared with only 21% at the postguideline survey. Pain assessment and documentation also improved significantly. CONCLUSION: The Quality Improvement Council felt that improvements in pain management were due largely to their having provided staff with the right tools to use in assessing, documenting, and controlling pain. Gains in pain management continue to be made.

Transplant nurses: concerns and opportunities.

Nurses caring for patients undergoing liver transplants were surveyed to identify specific needs and concerns. Previously identified issues in regard to orthotopic liver transplantation also were addressed: high mortality rates, time-consuming care, emotional factors and ethical issues. Nurses need to be represented on selection and ethics committees and to participate in clinical decisions.

Case study: when the nurse and physician don't agree.

Nurses and physicians by virtue of their roles as health care professionals must work together to provide care for their patients. Decisions regarding life support and death and dying are made almost daily in most intensive care units. Conflicts frequently arise among health care providers when decisions of this nature are made. Nurses and physicians, despite having similar value systems, operate under a different frame of reference. Understanding the differences and how they play themselves out in the clinical setting can alleviate much of the stress and frustration common when these issues are encountered. This article examines the value systems and perspectives of nurses and physicians using a case study format.

Thromboembolic phenomena.

Venous thrombosis and thromboembolic phenomenon affect over 2 million people each year. Estimates indicate that there are 50,000 deaths from pulmonary embolus annually and that this number has not declined in 20 years. Understanding the etiology and prevention of this complication is essential to the critical care health care practitioner.

Nucleotide sequence and over-expression of morphine dehydrogenase, a plasmid-encoded gene from Pseudomonas putida M10.

Pseudomonas putida M10 was originally isolated from factory waste liquors by selection for growth on morphine. The NADP(+)-dependent morphine dehydrogenase that initiates morphine catabolism is encoded by a large plasmid of 165 kb. Treatment of P. putida M10 with ethidium bromide led to the isolation of a putative plasmid-free strain that was incapable of growth on morphine. The structural gene for morphine dehydrogenase, morA, has been located on the plasmid by oligonucleotide hybridization, by coupled transcription-translation of cloned restriction fragments and by nucleotide sequence analysis and is contained within a 1.7 kb SphI fragment that has been cloned into Escherichia coli. The cloned dehydrogenase enzyme is expressed at high levels in E. coli resulting in a 65-fold increase in morphine dehydrogenase activity in cell-free extracts compared with P. putida M10. Morphine dehydrogenase was rapidly purified to homogeneity, as judged by SDS/PAGE, by a one-step affinity chromatography procedure on Mimetic Orange 3 A6XL. The properties of the purified enzyme were identical with those previously reported for P. putida M10 morphine dehydrogenase. The morA gene was sequenced and the deduced amino acid sequence confirmed by N-terminal amino acid sequencing of the over-expressed protein. The predicted amino acid sequence of morA, deduced from the nucleotide sequence, indicated that morphine dehydrogenase did not belong to the non-metal-requiring short-chain class of dehydrogenases, but was more closely related to the aldo-ketoreductases.

Reperfusion injury.

The paradigm of reperfusion is one that will test the skills of the critical care practitioner. This syndrome has been implicated in many of the disorders commonly encountered in the intensive care unit. As research continues and more knowledge is gained into the evolution of this process, many of the complications caused by this affliction will be eliminated. In the interim, understanding of the pathophysiology and the components of this syndrome will assist in providing quality care for the patient unfortunate enough to have encountered this potentially devastating malady.

The dying patient in the critical care setting: making the critical difference.

Death is an inevitable fact in the critical care setting. This fact does not make it more comfortable for the nurse who is caring for a critically ill patient who is dying. Some health care providers have recommended that the critical care resources are better utilized for the patient whose prognosis is not death. This position can be countered with the perspective that there may be no better place to provide the intensive nursing care that the dying patient may need than the critical care setting. A new nursing diagnosis, Terminal Syndrome related to the dying process is introduced to assist the nurse in providing comprehensive care for what is often a complex patient care situation. The goal is to achieve for each dying individual in the critical care setting what she or he truly desires, an end to the life process, a death achieved with comfort and dignity.

Brain resuscitation. Ethical perspectives.

Brain resuscitation is the newest in a long line of treatment protocols that is designed to aid us in sustaining not just life, but quality life in the critical care setting. Like other, previously established protocols, it is not value free. Its implementation brings ethical considerations that must be addressed. If the issues are not addressed, there is the real danger that the resulting moral dilemmas will overwhelm the nurse. In brain resuscitation, there are at least three ethical issues that must be recognized. These are the role of resuscitation in the life process, allocation of scarce resources, and participation in research. To address these issues, nurses will have to be aware of the ethical principle and/or perspectives involved. For some of these issues, the solutions will have to come from nursing's national organizations, such as the American Association of Critical Care Nurses. Other solutions presented will require the nurse to come to an individual decision regarding the ethics of brain resuscitation. The journey to the conclusion of this discussion will end with disappointment for those who sought an algorhythm or decision tree with which to make definitive decisions in regard to ethical decisions about brain resuscitation. To have assumed that such an absolute discussion in regard to the ethical perspectives related to brain resuscitation is possible or even desirable would have been to deny the moral/ethical responsibilities of the nurse who practices in a critical care setting. While these ethical responsibilities can be overwhelmingly burdensome, they can also be opportunities. They can be positive opportunities for our health care colleagues, our patients, and ourselves.

A nursing perspective of the ethical issues surrounding liver transplantation.

Nurses who care for patients undergoing liver transplantation increasingly face a variety of ethical issues. These issues include but are not limited to consent, selection of recipients, and allocation of scarce resources. Nurses have ethical concerns related to these issues that are specific to nursing. These nursing concerns differ in perspective, context, and content from the concerns of fellow health professionals or the lay public. For the nurse, the concern regarding consent may be not whether the consent was informed, but rather whether the consent was freely given. The scarce resource about which the nurse is most concerned is not so much the organ as it is professional nursing care. For the nurse to address these ethical concerns, strategies will have to be implemented at the unit, institutional, and professional level.

Tyrosine and tryptophan modification monitored by ultraviolet resonance Raman spectroscopy.

Nitration of tyrosine with tetranitromethane shifts the tyrosine absorption spectrum and abolishes its 200 nm-excited resonance Raman spectrum. There is no detectable resonance Raman contribution from either reactants or products. Likewise, modification of tryptophan with 2-hydroxy-5-nitrobenzyl bromide (HNBB) shifts its absorption spectrum and abolishes its 218 nm-excited resonance Raman spectrum. In this case resonance Raman bands due to HNBB are seen, but are readily distinguishable from the tryptophan spectrum, can be computer-subtracted. When stellacyanin was treated with tetranitromethane the UV resonance Raman spectrum was greatly attenuated; quantitation of the 850 cm-1 tyrosine band intensity gave a value of 4.3 tyrosines modified out of the seven present in stellacyanin, in good agreement with an estimate of 4.7 from the absorption spectrum. For cytochrome c, the resonance Raman spectrum indicates that two out of the four tyrosines are modified by tetranitromethane treatment, consistent with the crystal structure, which shows two buried tyrosines and two at the protein surface. Treatment of stellacyanin with HNBB gave a reduction in the tryptophan spectrum, excited at 218 nm, consistent with one of the three tryptophans being modified. These modification procedures should be useful in distinguishing spectra of buried tyrosine and tryptophan residues from those at the surface.

Studies on the effect of feeding nitrite and secondary amines to Wistar rats.

1. When 1 000 mg/l sodium nitrite are added to drinking-water, nitrosamines are formed in the stomachs of Wistar rats at levels greater than the background only if the concentrations of added DMA or pyrrolidine exceed 1 000 mg/kg. Once this concentration is exceeded there is a rapid increase in nitrosamine formation up to 2 000 mg/kg added amine; however, for pyrrolidine, the rate of increase of NPy decreases when the dietary level of amine exceeds 2 000 mg/kg. This threshold level of 1 000 mg/kg amine is one which is rarely reached in normal human dietary patterns. 2. Due to the presence of this threshold it is unrealistic to extrapolate from high experimental dietary concentrations of secondary amines to those found in practice when considering nitrosamine formation in vivo. 3.The concentration of dietary amine has a greater influence on nitrosamine formation in the stomachs of rats than does the concentration of nitrite in drinking-water (up to 1 000 mg/l). This finding is in contradiction to the current kinetic theory of nitrosamine formation, in which formation is predicted to be proportional to the square of the nitrite concentration.