Evaluating a neonatal intensive care unit MRSA surveillance programme using agent-based network modelling.

BACKGROUND: Surveillance for meticillin-resistant Staphylococcus aureus (MRSA) in neonatal intensive care units (NICUs) is a commonplace infection prevention strategy, yet the optimal frequency with which to monitor the unit is unknown. AIM: To compare various surveillance frequencies using simulation modelling. METHODS: One hundred NICU networks of 52 infants were simulated over a six-month period to assess MRSA transmission. Unit-wide surveillance occurred every N weeks where N={1,2,3,4}, and was compared with the current NICU policy of dynamic surveillance (i.e. weekly when at least one positive screen, otherwise every three weeks). For each surveillance period, colonized infants received a decolonization regimen (56% effective) and were moved to isolation rooms, if available. FINDINGS: As the surveillance frequency increased, the mean number of MRSA-colonized infants decreased, from a high of 2.9 (four-weekly monitoring) to a low of 0.6 (weekly monitoring) detected per episode. The mean duration of colonization decreased from 307 h (four-weekly monitoring) to 61 h (weekly monitoring). Meanwhile, the availability of isolation rooms followed an inverse relationship: as surveillance frequency increased, the availability of isolation rooms decreased (61% isolation success rate for four-weekly monitoring vs 49% success rate for weekly monitoring). The dynamic policy performed similar to a biweekly programme. CONCLUSIONS: An effective MRSA surveillance programme needs to balance resource availability with potential for harm due to longer colonization periods and opportunity for development of invasive disease. While more frequent monitoring led to greater use of a decolonization regimen, it also reduced the likelihood of isolation rooms being available.

Structure-activity studies on high affinity NOP-active hexapeptides.

Nociceptin/orphanin FQ (N/OFQ) is a 17 amino acid peptide that is the endogenous ligand for the G-protein coupled receptor ORL1 (NOP), a member of the opioid receptor family. Although it is clear that this receptor system is involved in a variety of physiologic functions, including analgesia, the precise actions of N/OFQ remain largely uncharacterized. One reason for this has been limited number of high-affinity ligands to NOP, and particularly the lack of availability of useful specific antagonists. Herein, we describe the pharmacologic activity of a series of modified amino acid containing modifications of the hexapeptide Ac-RYYRWR-NH2, with high affinity for NOP. These compounds were tested for binding affinity using [3H]N/OFQ binding to human NOP in CHO cells, and functional activity by measuring stimulation of [35S]GTPgammaS-binding in CHO cell membranes. These studies suggest that each Arg of the hexapeptide is required to maintain high-binding affinity. The peptide maintains high affinity if the Tyr2 or Tyr3 are modified, but at least one of these residues must maintain its hydroxyl group or there is a large decrease in intrinsic activity of the peptide.

Electronic reporting to improve patient safety.

BACKGROUND: Limited data are available on the experiences of voluntary event reporting systems to improve patient safety. OBJECTIVE: Development and implementation of educational initiatives to facilitate the use of an electronic reporting system (ERS) in an academic medical center to measure the impact on knowledge of the ERS on reporting behavior and safety attitudes and to evaluate the accuracy of the information being reported. METHODS: A voluntary internal confidential electronic system for reporting safety events was implemented which involved patients and visitors. A multifaceted educational program was developed to promote safety awareness and use of the ERS system. The safety event detail reported for the calendar year 2002 was tracked and trended and central event analyses were performed for five high event clinical areas. A survey was administered to assess safety knowledge and attitudes of patient care personnel. RESULTS: 2843 safety events were entered into the ERS during 2002 with an increase during the course of the year (p = 0.055, linear trend) for all events. Nurses entered 73% of the events and physicians only 2%. 453 events (16%) were unsafe conditions or near misses and 623 (22%) were associated with patient harm. System factors were considered by the reporter as contributing to the event in only a few cases (5%). Central event analysis revealed that 39% of events had coding errors either in event classification, level of impact, or location; significant underreporting was also present. Although survey response rates were low (10.3%), responders showed a high degree of knowledge on general questions of patient safety and an increase in knowledge on use of the ERS (p = 0.0015, linear trend). CONCLUSIONS: Knowledge on the use of the reporting system and the frequency of reported events increased over the first year of the study. More work is needed to involve physicians in reporting, to improve the accuracy of submitted information, and to better prioritize, organize, and streamline event analysis.

N-terminal modifications leading to peptide ORL1 partial agonists and antagonists.

Nociceptin/Orphanin FQ (N/OFQ) is a 17 amino acid peptide that is the endogenous ligand for the G protein-coupled receptor (opioid receptor like 1, ORL1), a member of the opioid receptor family. Although it is clear that this receptor system is involved in a variety of physiological functions, including analgesia, the precise actions of N/OFQ remain largely uncharacterized. One reason for this has been limited high affinity ligands to ORL1, and particularly the lack of availability of useful specific antagonists. Herein we describe the pharmacological activity of a series of N-terminally modified hexapeptides with high affinity for ORL1. These compounds were tested for binding affinity using [3H]N/OFQ binding to human ORL1 in CHO cells, and functional activity by measuring stimulation of [35S]GTPgammaS binding in CHO cell membranes. The N-terminal modifications have produced compounds that maintained very high receptor affinity, but led to significant changes in intrinsic activity. One compound, pentanoyl-RYYRWR-NH2, with barely measurable agonist activity was tested in vivo. It was found to possess modest analgesic activity, but it was unable to block the morphine modulatory activity of N/OFQ.

Preeclampsia does not increase the risk for culture proven sepsis in very low birth weight infants.

The risk of sepsis associated with neutropenia in infants born to mothers with preeclampsia remains controversial. The objective of this study is to investigate the incidence of culture-proven sepsis along with changes in the complete blood count in very-low-birth-weight infants born to mothers with preeclampsia. We conducted a retrospective cohort study of infants cared for at a single tertiary care neonatal intensive care unit during a 4-year period. Infants born to mothers with preeclampsia (n = 88) were compared to infants born to mothers without preeclampsia (n = 416) by univariate and multivariate analysis. Although infants born to mothers with preeclampsia had lower absolute neutrophil and platelet counts throughout the first week of life, they were no more likely to have a platelet count <100,000 /mm3, and only more likely to be neutropenic at 24 and 72 hr of life compared to infants born to mothers without preeclampsia. After controlling for potential confounding variables, there was no increase in the odds of culture proven sepsis in infants born to mothers with preeclampsia (odds ratio 1.6, 95% confidence intervals 0.7-3.6, p = 0.3) compared to those infants born to mothers without preeclampsia. We conclude that very-low-birth-weight infants born to mothers with preeclampsia are not at increased risk of culture proven sepsis despite a reduction in absolute neutrophils.

Expression of CCR5 increases during monocyte differentiation and directly mediates macrophage susceptibility to infection by human immunodeficiency virus type 1.

The stage of differentiation and the lineage of CD4+ cells profoundly affect their susceptibility to infection by human immunodeficiency virus type 1 (HIV-1). While CD4(+) T lymphocytes in patients are readily susceptible to HIV-1 infection, peripheral blood monocytes are relatively resistant during acute or early infection, even though monocytes also express CD4 and viral strains with macrophage (M)-tropic phenotypes predominate. CCR5, the main coreceptor for M-tropic viruses, clearly contributes to the ability of CD4+ T cells to be infected. To determine whether low levels of CCR5 expression account for the block in infection of monocytes, we examined primary monocyte lineage cells during differentiation. Culturing of blood monocytes for 5 days led to an increase in the mean number of CCR5-positive cells from <20% of monocytes to >80% of monocyte-derived macrophages (MDM). Levels of CCR5 expression per monocyte were generally lower than those on MDM, perhaps below a minimum threshold level necessary for efficient infection. Productive infection may be restricted to the small subset of monocytes that express relatively high levels of CCR5. Steady-state CCR5 mRNA levels also increased four- to fivefold during MDM differentiation. Infection of MDM by M-tropic HIV-1JRFL resulted in >10-fold-higher levels of p24, and MDM harbored >30-fold more HIV-1 DNA copies than monocytes. In the presence of the CCR5-specific monoclonal antibody (MAb) 2D7, virus production and cellular levels of HIV-1 DNA were decreased by >80% in MDM, indicating a block in viral entry. There was a direct association between levels of CCR5 and differentiation of monocytes to macrophages. Levels of CCR5 were related to monocyte resistance and macrophage susceptibility to infection because infection by the M-tropic strain HIV-1JRFL could be blocked by MAb 2D7. These results provide direct evidence that CCR5 functions as a coreceptor for HIV-1 infection of primary macrophages.

Glucose-induced microautophagy in Pichia pastoris requires the alpha-subunit of phosphofructokinase.

We have characterized biochemically, morphologically, and genetically two distinct pathways for the selective degradation of peroxisomes in Pichia pastoris. These pathways are independently regulated and analogous to microautophagy and macroautophagy that have been defined in mammalian cells. When P. pastoris is grown in methanol, cytosolic and peroxisomal enzymes necessary for methanol assimilation are synthesized. During adaptation from methanol to glucose, these enzymes are rapidly and selectively degraded within the yeast vacuole by microautophagy. We have isolated gsa mutants that are defective in glucose-induced selective autophagy of peroxisomes. In this study, we have shown that gsa1 is unable to sequester peroxisomes into the yeast vacuole. In addition, we provide evidence that the glucose-induced selective autophagy 1 (GSA1) protein is the alpha subunit of the phosphofructokinase enzyme complex encoded by PFK1. First, we can rescue the gsa1 mutant by transformation with a vector containing PFK1. Second, cellular levels of both PFK1 mRNA and phosphofructokinase activity are dramatically reduced in gsa1 when compared to the parental GS115. Third, a PFK1 knockout (delta pfk1) is unable to degrade alcohol oxidase during glucose adaptation. As observed in gsa1, the peroxisomes in delta pfk1 remain outside the vacuole during adaptation. Our data are consistent with the concept that PFK1 protein is required for an event upstream of vacuole degradation (i.e. signaling, selection, or sequestration). However, the degradation of peroxisomes does not require a catalytically active phosphofructokinase. The inability of delta pfk1 cells to degrade alcohol oxidase can be rescued by transformation with either normal PFK1 or mutant pfk1 whose catalytic site had been inactivated by a single amino acid mutation. We propose that PFK1 protein directly modulates glucose-induced microautophagy independent of its ability to metabolize glucose intermediates.

1995 Fast Track: cost reduction and improvement.

To respond to a cost reduction crisis, Strong Memorial Hospital implemented an aggressively managed program of accelerated improvement teams. "Fast-track" teams combined the application of many management tools (total quality management, breakthrough thinking, reengineering, etc.) into one problem-solving process. Teams and managers were charged to work on specific cost reduction strategies. Teams were given additional instruction on interpersonal skills such as communication, teamwork, and leadership. Paradoxically, quality improvement in our hospital was advanced more through this effort at cost reduction than had previously been done in the name of quality itself.

Hairy polyp of the oropharynx: case report and literature review.

Hairy polyp of the oronasopharynx is an uncommon developmental malformation that is most frequently seen as a pedunculated tumor in the neonate. Derived from the ectoderm and mesoderm, this benign tumor generally has been classified as dermoid. The clinical presentation is dependent on the polyp's size and location. A full-term girl was evaluated for an oral mass that was first noted at the time of birth. Evaluation showed a 5- x 2.5-cm soft, nontender, skin-covered mass that protruded from the oral cavity. During surgery, it was noted that the stalk was attached to the superior pole of the left tonsil. The histology of the mass was consistent with a hairy polyp. Knowledge of this type of malformation facilitates early intervention and avoids significant morbidity.

Preventing perioperative transmission of infection: a survey of anesthesiology practice.

Given the societal and economic impact of perioperative infection, it is essential that anesthesiologists and other operating room personnel use appropriate precautions to reduce the potential for transmission of infectious agents to the patients under their care. This study, therefore, was designed to evaluate the degree to which anesthesiologists utilize appropriate hygienic techniques for the prevention of infection in the perioperative period. A total of 1149 questionnaires were mailed to anesthesiologists randomly selected from the membership of the American Society of Anesthesiologists (ASA). Of these, 493 (44%) were completed and returned. Forty-nine percent and 75.3% of respondents always used gloves and masks, respectively, in their everyday practice. Only 58% of respondents stated that they always washed their hands after every patient contact and 85% reported that they always used aseptic technique for placing indwelling catheters. Knowledge of universal precautions for prevention of occupational transmission of infection was associated with good hygienic practice. Twenty percent of the respondents reported frequently or always reusing syringes for more than one patient and 34.4% reported never or rarely disinfecting the septum of multidose vials prior to use. The practice of reusing syringes was significantly greater among private than university practitioners (P < 0.01). On a scale of 0-10 (10 = high) anesthesiologists rated their potential for transmitting or contributing to patient potential for transmitting or contributing to patient infection as 4.7 +/- 0.12 (mean +/- SE). Results of this study suggest that, whereas most responding anesthesiologists exhibit appropriate infection control behaviors, there are several potentially hazardous practices that continue.

Divergent modes of autophagy in the methylotrophic yeast Pichia pastoris.

The budding yeast Pichia pastoris responds to methanolic media by synthesizing high levels of cytosolic enzymes (e.g. formate dehydrogenase) and peroxisomal enzymes (e.g. alcohol oxidase), which are necessary to assimilate this carbon source. Major alterations in cellular metabolism are initiated upon a shift in carbon source to ethanol or glucose. These alterations require the synthesis of new proteins and the rapid degradation of those enzymes no longer needed for methanol utilization. In this study, we have measured cytosolic and peroxisomal enzyme activities and examined the fate of morphologically distinct peroxisomes to assess the degradative response of this yeast during nutrient adaptation. Utilizing biochemical, morphological and genetic approaches, we have shown that there exist in P. pastoris at least two pathways for the sequestration of peroxisomes into the vacuole for degradation. The ethanol-induced pathway is independent of protein synthesis and includes an intermediate stage in which individual peroxisomes are sequestered into autophagosomes by wrapping membranes, which then fuse with the vacuole. This process is analogous to macroautophagy. The glucose-induced pathway invokes the engulfment of clusters of peroxisomes by finger-like protrusions of the vacuole by a process analogous to microautophagy. Unlike ethanol adaptation, glucose stimulated the degradation of formate dehydrogenase as well. Peroxisomes remained outside the vacuoles of glucose-adapted cycloheximide-treated normal cells, suggesting that protein synthesis is required for peroxisome entry into the yeast vacuole. Two complementary mutants (gsa1 and gsa2) that are unable to degrade peroxisomes or formate dehydrogenase during glucose adaptation were isolated. The mutated gene products appear to function in one or more events upstream of degradation within the vacuole, since ethanol-induced peroxisome degradation proceeded normally in these mutants and peroxisomes were found outside the vacuoles of glucose-adapted gsa2 cells. Mutants lacking vacuolar proteinases A and B were unable to degrade alcohol oxidase or formate dehydrogenase during ethanol or glucose adaptation. Peroxisomes were found to accumulate within the vacuoles of these proteinase mutants during adaptation. Combined, the results suggest that there exist in Pichia pastoris two independent pathways for the sequestration of peroxisomes into the vacuole, the site of degradation.

Prevention of occupational transmission of human immunodeficiency virus and hepatitis B virus among anesthesiologists: a survey of anesthesiology practice.

In light of the increasing prevalence of the human immunodeficiency virus (HIV) and hepatitis B virus (HBV), anesthesiologists are now likely to see more patients who are at high risk for these viruses. Therefore, it is important that they adopt infection control policies aimed at preventing occupational transmission of these and other pathogens during their clinical practice. This study was designed, using a questionnaire format, to evaluate anesthesiologist compliance with Centers for Disease Control (CDC) guidelines for the prevention of occupational transmission of HIV and HBV. A total of 1149 questionnaires were mailed to anesthesiologists randomly selected from the members' directory of the American Society of Anesthesiologists (ASA). Of these, 493 (44%) were completed and returned. Eighty-eight percent of respondents reported that they always complied with CDC guidelines when presented with an HIV-infected patient, but only 24.7% adhered to the guidelines when the patient was considered low risk (P < 0.01). This trend was also reflected in the use of gloves and other protective wear in the perioperative period. Although 70% of respondents indicated that they recapped needles on a regular basis, this practice was not associated with an increased incidence of needlestick injuries. However, anesthesiologists who reported recapping needles using the one-handed technique were less likely to sustain a needlestick injury than those who recapped using the two-handed technique. Thirty-one percent and 72% of respondents respectively reported a clean or contaminated needlestick within the preceeding 12 mo. Only 45.4% of those receiving a contaminated needlestick sought treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Selective autophagy of peroxisomes in methylotrophic yeasts.

The methylotrophic yeasts Pichia pastoris and Hansenula polymorpha respond to a methanol substrate by synthesizing peroxisomal enzymes resulting in the formation of large peroxisomes. When the carbon source was changed from methanol to glucose, we observed a rapid loss of peroxisomes. In this comparative study, we utilized biochemical and morphological techniques to characterize the loss of peroxisomes in these yeasts. We used metabolic labeling and chase procedures to evaluate whether this loss was due to suppressed synthesis or enhanced degradation. The synthesis of alcohol oxidase was depressed 10-fold when cultures grown in methanol attained stationary growth. However, no further reduction of synthesis was observed upon transfer of these cultures to glucose medium. In stationary phase cultures maintained in methanol, two peroxisomal proteins, alcohol oxidase and dihydroxyacetone synthase, were degraded with a half-life of over 3 h. However, within 3 h of glucose repression, as much as 80% of the radiolabeled peroxisomal proteins were lost from both yeasts. This glucose-mediated degradative event appeared to be specific for peroxisomal proteins, since mitochondrial proteins were stable. Ultrastructural examination of both yeasts revealed that glucose induced the sequestration of peroxisomes into the yeast vacuole, the presumed site of degradation. These results suggest that peroxisome loss during glucose repression is due to a selective, enhanced degradation of whole peroxisomes by autophagic mechanisms.