Fast, High-Fidelity Addressed Single-Qubit Gates Using Efficient Composite Pulse Sequences

We use electronic microwave control methods to implement addressed single-qubit gates with high speed and fidelity, for ^{43}Ca^{+} hyperfine "atomic clock" qubits in a cryogenic (100 K) surface trap. For a single qubit, we benchmark an error of 1.5×10^{-6} per Clifford gate (implemented using 600 ns π/2 pulses). For 2 qubits in the same trap zone (ion separation 5  μm), we use a spatial microwave field gradient, combined with an efficient four-pulse scheme, to implement independent addressed gates. Parallel randomized benchmarking on both qubits yields an average error 3.4×10^{-5} per addressed π/2 gate. The scheme scales theoretically to larger numbers of qubits in a single register.

Obesity and surgical complications of pancreaticoduodenectomy: An observation study utilizing ACS NSQIP

BACKGROUND

An estimated 38% of US adults are obese. Obesity is associated with socioeconomic disparities and increased rates of comorbidities, and is a known risk factor for development of pancreatic cancer. As a fourth leading cause of death in the United States, pancreatic cancer is commonly treated with a pancreatico-duodenectomy (PD), or Whipple procedure. Data regarding the effects of obesity on post-operative complication rate primarily comes from specialized centers, however the results are mixed. Our aim is to elucidate the effects that obesity has on outcomes after PD for pancreatic head cancer using a national prospectively maintained clinical database.

METHOD

The 2010-2015 American College of Surgeons National Surgical Quality Improvement Project (ACS NSQIP) Participant Use Files (PUF) were used as the data source. We identified cases in which PD was performed (CPT code 48150) in the setting of a postoperative diagnosis of pancreatic cancer (ICD9 code 157.0). We excluded cases that had emergency admissions, BMI ≤18.5 kg/m², intraoperative wound classification of III or IV, and disseminated cancer. Cases with missing BMI, preoperative albumin, operative time, LOS data were also excluded. Multiple imputation for missing sex, race, functional status, and ASA classification using chained equations was performed.¹⁶ Patients that had BMI ≥30 kg/m² were considered obese, and patients with BMI <30 kg/m² were used as control.

RESULTS

3484 patients underwent pancreaticoduodenectomy for pancreatic cancer. 860 patients were identified as obese. Propensity score analysis was performed matching age, sex, race, functional status, presence of dyspnea, diabetes, hypertension, acute renal failure, dialysis dependence, ascites, steroid use, bleeding disorders, history of chronic obstructive pulmonary disease (COPD), congestive heart failure (CHF), weight loss, American Society of Anesthesiologists (ASA) classification, and preoperative albumin levels. After matching, obese patients had higher risk of 30-day postoperative complications compared to control, including organ space wound infections (OR 1.38, 95% CI 1.07-1.79, p = 0.0128), returning to the operating room (OR 1.39, 95% CI 1.01-1.91, p = 0.0461), failure to extubate for greater than 48 h (OR 1.60, 95% CI 1.09-2.34, p = 0.0153), death (OR 1.68, 95% CI 1.01-2.78, p = 0.0453), septic shock (OR 2.22, 95% CI 1.46-3.38, p = 0.0002), pulmonary embolism (OR 2.42, 95% CI 1.07-5.45, p = 0.0332), renal insufficiency (OR 2.67, 95% CI 1.33-5.38, p = 0.0058). Sensitivity analysis yielded similar results with the exception of risk for return to the operating room, death, and pulmonary embolism, P > .05.

CONCLUSION

In this large observational study using a national clinical database, obese patients undergoing PD for head of pancreas cancer had increased risk of postoperative complications and mortality in comparison to controls.

Episodic temporal generalization: A developmental study

Groups of 5-year-olds, 10-year-olds, and adults completed either an episodic temporal generalization task, in which no stimuli were repeated, or a repeated standard temporal generalization task, in which there was a fixed standard that was repeated on every trial. Significant developmental improvements were found on both tasks. In both tasks, gradients of performance over two different stimulus ranges superimposed well when plotted on the same relative scale. Performance was similar for the adults and 10-year-olds across tasks, but the 5-year-olds performed better on the repeated standard task. These findings suggest that perceptual processes are a source of scalar variability in timing, and that there are developmental changes in levels of such variability.

Rates of hip and knee joint replacement amongst different ethnic groups in England: an analysis of National Joint Registry data

OBJECTIVE

Despite a health care system that is free at the point of delivery, ethnic minorities may not always get care equitable to that of White patients in England. We examined whether ethnic differences exist in joint replacement rates and surgical practice in England.

DESIGN

373,613 hip and 428,936 knee National Joint Registry (NJR) primary replacement patients had coded ethnicity in Hospital Episode Statistics (HES). Age and gender adjusted observed/expected ratios of hip and knee replacements amongst ethnic groups were compared using indirect standardisation. Associations between ethnic group and type of procedure were explored and effects of demographic, clinical and hospital-related factors examined using multivariable logistic regression.

RESULTS

Adjusted standardised observed/expected ratios were substantially lower in Blacks and Asians than Whites for hip replacement (Blacks 0.33 [95% CI, 0.31-0.35], Asians 0.20 [CI, 0.19-0.21]) and knee replacement (Blacks 0.64 [CI, 0.61-0.67], Asians 0.86 % [CI, 0.84-0.88]). Blacks were more likely to receive uncemented hip replacements (Blacks 52%, Whites 37%, Asians 44%; P < 0.001). Black men and women aged <70 years were less likely to receive unicondylar or patellofemoral knee replacements than Whites (men 10% vs 15%, P = 0.001; women 6% vs 14%, P < 0.001). After adjustment for demographic, clinical and hospital-related factors, Blacks were more likely to receive uncemented hip replacement (OR 1.43 [CI, 1.11-1.84]).

CONCLUSIONS

In England, hip and knee replacement rates and prosthesis type given differ amongst ethnic groups. Whether these reflect differences in clinical need or differential access to treatment requires urgent investigation.

Magnetic Nanodrug Delivery Through the Mucus Layer of Air-Liquid Interface Cultured Primary Normal Human Tracheobronchial Epithelial Cells

Superparamagnetic iron oxide (Fe₃O₄) and highly anisotropic barium hexaferrite (BaFe₁₂O₁₉) nanoparticles were coated with an anti-inflammatory drug and magnetically transported through mucus produced by primary human airway epithelial cells. Using wet planetary ball milling, dl-2-amino-3-phosphonopropionic acid-coated BaFe₁₂O₁₉ nano-particles (BaNPs) of 1-100 nm in diameter were prepared in water. BaNPs and conventional 20-30-nm Fe₃O₄ nanoparticles (FeNPs) were then encased in a polymer (PLGA) loaded with dexamethasone (Dex) and tagged for imaging. PLGA-Dex-coated BaNPs and FeNPs were characterized using dynamic light scattering (DLS), transmission electron microscopy (TEM), and superconducting quantum interference device (SQUID) magnetometry. Both PLGA-Dex-coated BaNPs and FeNPs were transferred to the surface of a ~100-μm thick mucus layer of air-liquid interface cultured primary normal human tracheobronchial epithelial (NHTE) cells. Within 30 min, the nanoparticles were pulled successfully through the mucus layer by a permanent neodymium magnet. The penetration time of the nanomedicine was monitored using confocal microscopy and tailored by varying the thickness of the PLGA-Dex coating around the particles.

Nasonov pheromone of the honey bee,Apis mellifera L. (Hymenoptera, Apidae). part III. : Regulation of pheromone composition and production

GC and GC-MS analyses of the multicomponent Nasonov pheromone of the honey bee, and of the air above insects releasing the pheromone, show that constant composition is maintained during release, despite differing volatilities of the components. The regulating mechanism may involve a specific enzyme process, detected in excised Nasonov glands, which converts the major component geraniol into the more volatile (E)-citral. Analysis of honey bees of known ages and at different times of year shows that maximum secretion occurs when foraging is most likely.

Discovery and characterization of LY2784544, a small-molecule tyrosine kinase inhibitor of JAK2V617F

Owing to the prevalence of the JAK2V617F mutation in myeloproliferative neoplasms (MPNs), its constitutive activity, and ability to recapitulate the MPN phenotype in mouse models, JAK2V617F kinase is an attractive therapeutic target. We report the discovery and initial characterization of the orally bioavailable imidazopyridazine, LY2784544, a potent, selective and ATP-competitive inhibitor of janus kinase 2 (JAK2) tyrosine kinase. LY2784544 was discovered and characterized using a JAK2-inhibition screening assay in tandem with biochemical and cell-based assays. LY2784544 in vitro selectivity for JAK2 was found to be equal or superior to known JAK2 inhibitors. Further studies showed that LY2784544 effectively inhibited JAK2V617F-driven signaling and cell proliferation in Ba/F3 cells (IC₅₀=20 and 55 nM, respectively). In comparison, LY2784544 was much less potent at inhibiting interleukin-3-stimulated wild-type JAK2-mediated signaling and cell proliferation (IC₅₀=1183 and 1309 nM, respectively). In vivo, LY2784544 effectively inhibited STAT5 phosphorylation in Ba/F3-JAK2V617F-GFP (green fluorescent protein) ascitic tumor cells (TED₅₀=12.7 mg/kg) and significantly reduced (P<0.05) Ba/F3-JAK2V617F-GFP tumor burden in the JAK2V617F-induced MPN model (TED₅₀=13.7 mg/kg, twice daily). In contrast, LY2784544 showed no effect on erythroid progenitors, reticulocytes or platelets. These data suggest that LY2784544 has potential for development as a targeted agent against JAK2V617F and may have properties that allow suppression of JAK2V617F-induced MPN pathogenesis while minimizing effects on hematopoietic progenitor cells.

Discovery and characterization of LY2784544, a small-molecule tyrosine kinase inhibitor of JAK2V617F

Owing to the prevalence of the JAK2V617F mutation in myeloproliferative neoplasms (MPNs), its constitutive activity, and ability to recapitulate the MPN phenotype in mouse models, JAK2V617F kinase is an attractive therapeutic target. We report the discovery and initial characterization of the orally bioavailable imidazopyridazine, LY2784544, a potent, selective and ATP-competitive inhibitor of janus kinase 2 (JAK2) tyrosine kinase. LY2784544 was discovered and characterized using a JAK2-inhibition screening assay in tandem with biochemical and cell-based assays. LY2784544 in vitro selectivity for JAK2 was found to be equal or superior to known JAK2 inhibitors. Further studies showed that LY2784544 effectively inhibited JAK2V617F-driven signaling and cell proliferation in Ba/F3 cells (IC50=20 and 55 nM, respectively). In comparison, LY2784544 was much less potent at inhibiting interleukin-3-stimulated wild-type JAK2-mediated signaling and cell proliferation (IC50=1183 and 1309 nM, respectively). In vivo, LY2784544 effectively inhibited STAT5 phosphorylation in Ba/F3-JAK2V617F-GFP (green fluorescent protein) ascitic tumor cells (TED50=12.7 mg/kg) and significantly reduced (P<0.05) Ba/F3-JAK2V617F-GFP tumor burden in the JAK2V617F-induced MPN model (TED50=13.7 mg/kg, twice daily). In contrast, LY2784544 showed no effect on erythroid progenitors, reticulocytes or platelets. These data suggest that LY2784544 has potential for development as a targeted agent against JAK2V617F and may have properties that allow suppression of JAK2V617F-induced MPN pathogenesis while minimizing effects on hematopoietic progenitor cells.

Patterns of alcohol use and multiple risk behaviour by gender during early and late adolescence: the ALSPAC cohort

BACKGROUND

Adolescent risk behaviours such as smoking, alcohol use and antisocial behaviour are associated with increased risk of morbidity and mortality. Patterns of risk behaviour may vary between genders during adolescence.

METHODS

Analysis of data from a longitudinal birth cohort to assess the prevalence and distribution of multiple risk behaviours by gender at age 15-16 years with a focus on alcohol use at age 10, 13 and 15 years.

RESULTS

By age 15 years, over half of boys and girls had consumed alcohol and one-fifth had engaged in binge drinking with no clear difference by gender. At age 15-16 years, the most prevalent risk behaviours were physical inactivity (74%), antisocial and criminal behaviour (42%) and hazardous drinking (34%). Boys and girls engaged in a similar number of behaviours but antisocial and criminal behaviours, cannabis use and vehicle-related risk behaviours were more prevalent among boys, whilst tobacco smoking, self-harm and physical inactivity were more prevalent among girls.

CONCLUSION

Multiple risk behaviour is prevalent in both genders during adolescence but the pattern of individual risk behaviour varies between boys and girls. Effective interventions at the individual, family, school, community or population level are needed to address gender-specific patterns of risk behaviour during adolescence.

Biodegradability of injection molded bioplastic pots containing polylactic acid and poultry feather fiber

The biodegradability of three types of bioplastic pots was evaluated by measuring carbon dioxide produced from lab-scale compost reactors containing mixtures of pot fragments and compost inoculum held at 58 °C for 60 days. Biodegradability of pot type A (composed of 100% polylactic acid (PLA)) was very low (13 ± 3%) compared to literature values for other PLA materials. Near infrared spectroscopy (NIRS) results suggest that the PLA undergoes chemical structural changes during polymer extrusion and injection molding. These changes may be the basis of the low biodegradability value. Biodegradability of pot types B (containing 5% poultry feather, 80% PLA, 15% starch), and C (containing 50% poultry feather, 25% urea, 25% glycerol), were 53 ± 2% and 39 ± 3%, respectively. More than 85% of the total biodegradation of these bioplastics occurred within 38 days. NIRS results revealed that poultry feather was not degraded during composting.

Mechanisms of vascular stability and the relationship to human disease

PURPOSE OF REVIEW

The genetic basis for a variety of vascular malformation syndromes have been described, with an increasing functional understanding of the associated genes.

RECENT FINDINGS

Genes responsible for familial vascular malformation syndromes have increasingly been shown to be involved in the control of vascular stability.

SUMMARY

Genes involved in vascular stability pathways are good candidates for causing vascular malformation syndromes. Although these findings confirm the biologic importance of the involved pathways, further explanations are required to describe the focal nature of disease.

Median labiomandibular glossotomy approach to the craniocervical region

INTRODUCTION

In children as well as adults, adequate access to the craniocervical junction and upper cervical vertebra can usually be achieved with a transoral-transpalatopharyngeal route. However, when access is necessary to achieve the C5 level and the upper cervical spine in children, this is very difficult. This is particularly so when the incisor opening is less than 2.5 cm. The median labiomandibular glossotomy provides such an approach.

MATERIALS AND METHODS

Our experience with five children is presented in a representative case: a 4-year-old male with a family history of spondyloepiphyseal dysplasia presented with mild quadriparesis, 2 years earlier. This had rapid progression with severe upper cervical kyphosis. A standard transoral-transpalatopharyngeal approach or a lateral extrapharyngeal approach would not achieve exposure of the pathology. Hence, a median labiomandibular glossotomy was utilized for ventral decompression with an anterior interbody fusion between C2 and C4. Crown halo cervical traction was placed intraoperatively before a tracheostomy and tonsillectomy. A median labiomandibular glossotomy was then made with resection of the displaced odontoid process and the vertebral bodies of C3 and C4. This was followed by an anterior interbody fusion between the C2 and C4 vertebrae with costal rib grafts.

RESULT AND CONCLUSION

He was successfully decannulated during the second postoperative week upon resolution of lingual edema. A planned staged dorsal occipitocervical fusion was performed 6 months later, at which time the ventral fusion was quite solid. He had full neurological recovery.

Assessment of glomerular filtration rate during pregnancy using the MDRD formula

It is now recommended practice to use estimated glomerular filtration rate (eGFR) values to screen for and monitor chronic renal disease. The most frequently used formula in the general population is that described following the Modification of Diet in Renal Disease (MDRD) study whereby serum creatinine is adjusted for age, gender and race. This study evaluates the performance of the MDRD formula in pregnancy by comparing eGFR with measured values obtained by inulin clearance studies in early and late normal pregnancy and in pregnancies complicated by renal disease or pre-eclampsia. Our results indicate that in all situations, MDRD substantially underestimates glomerular filtration rate during pregnancy and cannot be recommended for use in clinical practice.

Antibody and skin-test responses of sheep vaccinated against Johne's Disease

Current vaccines against Mycobacterium avium subsp. paratuberculosis (MAP, Johne's Disease) may cause animals to react positively when tested for Mycobacterium bovis (Bovis). Therefore, the effects of vaccination on MAP serum Ab and skin-test responses to MAP and Bovis PPD were compared in 25 ewes vaccinated against MAP with 24 control ewes in an infected flock 3 years post-vaccination. MAP-specific Ab levels were higher (P<0.001) in vaccinated ewes than in control ewes. All increases in skinfold-thickness from 0 to 48h were greater (P<0.0001) than zero while increases in skinfold-thickness from 48 to 72h were greater (P<0.05) than zero for Johnin but not for Bovis PPD. The Vaccine x PPD x Time interaction for skinfold-thickness was significant (P<0.001) with greater increases to Johnin than to Bovis, but with much greater increases in vaccinated ewes. These data suggest that administration of vaccines against MAP developed from whole organisms increase the likelihood that animals will be classified as "responders" to a Bovis screening test and negative by the follow-up comparative cervical tuberculin test, but they also show that vaccination initiates both humoral and cell-mediated MAP-specific responses.

Minimum speed limit for ocean ridge magmatism from 210Pb–226Ra–230Th disequilibria

Although 70 per cent of global crustal magmatism occurs at mid-ocean ridges-where the heat budget controls crustal structure, hydrothermal activity and a vibrant biosphere-the tempo of magmatic inputs in these regions remains poorly understood. Such timescales can be assessed, however, with natural radioactive-decay-chain nuclides, because chemical disruption to secular equilibrium systems initiates parent-daughter disequilibria, which re-equilibrate by the shorter half-life in a pair. Here we use 210Pb-226Ra-230Th radioactive disequilibria and other geochemical attributes in oceanic basalts less than 20 years old to infer that melts of the Earth's mantle can be transported, accumulated and erupted in a few decades. This implies that magmatic conditions can fluctuate rapidly at ridge volcanoes. 210Pb deficits of up to 15 per cent relative to 226Ra occur in normal mid-ocean ridge basalts, with the largest deficits in the most magnesium-rich lavas. The 22-year half-life of 210Pb requires very recent fractionation of these two uranium-series nuclides. Relationships between 210Pb-deficits, (226Ra/230Th) activity ratios and compatible trace-element ratios preclude crustal-magma differentiation or daughter-isotope degassing as the main causes for the signal. A mantle-melting model can simulate observed disequilibria but preservation requires a subsequent mechanism to transport melt rapidly. The likelihood of magmatic disequilibria occurring before melt enters shallow crustal magma bodies also limits differentiation and heat replenishment timescales to decades at the localities studied.

Application of monoclonal antibodies in functional and comparative investigations of heavy-chain immunoglobulins in new world camelids

Of the three immunoglobulin G (IgG) isotypes described to occur in camelids, IgG2 and IgG3 are distinct in that they do not incorporate light chains. These heavy-chain antibodies (HCAbs) constitute approximately 50% of the IgG in llama serum and as much as 75% of the IgG in camel serum. We have produced isotype-specific mouse monoclonal antibodies (MAbs) in order to investigate the roles of HCAbs in camelid immunity. Seventeen stable hybridomas were cloned, and three MAbs that were specific for epitopes on the gamma chains of llama IgG1, IgG2, or IgG3 were characterized in detail. Affinity chromatography revealed that each MAb bound its isotype in solution in llama serum. The antibodies bound to the corresponding alpaca IgGs, to guanaco IgG1 and IgG2, and to camel IgG1. Interestingly, anti-IgG2 MAbs bound three heavy-chain species in llama serum, confirming the presence of three IgG2 subisotypes. Two IgG2 subisotypes were detected in alpaca and guanaco sera. The MAbs detected llama serum IgGs when they were bound to antigen in enzyme-linked immunosorbent assays and were used to discern among isotypes induced during infection with a parasitic nematode. Diseased animals, infected with Parelaphostrongylus tenuis, did not produce antigen-specific HCAbs; rather, they produced the conventional isotype, IgG1, exclusively. Our data document the utility of these MAbs in functional and physiologic investigations of the immune systems of New World camelids.

Sex and the pregnant kidney: Does renal allograft gender influence gestational renal adaptation in renal transplant recipients?

BACKGROUND

Animal work indicates that ovarian hormones are important in initiating and maintaining enhanced renal function in pregnant rats and that a renal response resembling pregnancy can be provoked in male rats exposed to pregnancy hormones. Women becoming pregnant following renal transplantation provide an opportunity to compare the functional response of male and female allografts to the gestational endocrine environment.

METHODS

This retrospective observational study included 20 renal allograft recipients (age 29.7 +/- 2.4 yrs) (mean +/- SE) who had 22 pregnancies beyond 24 weeks (gestation at delivery 35.5 +/- 0.6 weeks). Donor characteristics, transplant details, renal follow-up data, and information about pregnancy and allograft function were obtained from hospital notes.

RESULTS

Thirteen women received male allografts (donor age 30.0 +/- 3.9 years) (mean +/- SEM) and 7 women, female allografts (donor age 45.1 +/- 6.0 years) (P = .04). There were no significant differences between the two groups in maternal recipient age, transplant to pregnancy interval, antenatal complications, pregnancy outcome, or postnatal graft function. Compared to prepregnancy values serum creatinine (SCr) decrements and augmented 24-hour creatinine clearance (CrCl) were observed over the first trimester in both male and female allografts: Delta CrCl from 106.8 +/- 13.2 mL/min to 114.4 +/- 11.4 mL/min (35.6% increase) and 71.8 +/- 7.4 to 89.5 +/- 11.3 mL/min (24.7% increase), respectively, and Delta SCr from 90.1 +/- 5.4 micromol/L to 73.6 +/- 6.6 micromol/L (17.8% decrease) and 99.8 +/- 9.7 micromol/L to 78.0 +/- 5.7 micromol/L (13.5% decrease), respectively. Differences between the two groups did not reach statistical significance.

CONCLUSIONS

Donor gender and/or age do not appear to influence the gestational renal response in kidney transplant recipients.

Using rotifer population demographic parameters to assess impacts of the degradation products from trinitrotoluene phytoremediation

The objective of this study was to evaluate the chronic lethal and sublethal aquatic toxicity effects associated with the phytoremediation of water contaminated with 2,4,6-trinitrotoluene (TNT) by the wetland plant species Myriophyllum aquaticum (parrot feather). Rotifers (Brachionus calyciflorus) feeding on an algal species (Nannochloropsis spp.) were used as the aquatic test organisms. Continuous flow laboratory microcosms were used to quantify effects on rotifer populations from TNT and the primary degradation product aminodinitrotoluene (ADNT) during and after phytoremediation. Rotifer demographic parameters from life tables, including survivorship, fecundity, reproductive values, net reproductive rate, generation time, intrinsic growth rate, and life expectancy, were used as measures of treatment effects. High-performance liquid chromatography analyses were performed to determine nitroaromatic concentrations. Results from this study have revealed significant differences in rotifer demographic parameters between microcosms with elevated initial TNT concentrations. Significant differences in demographic parameters also existed between the microcosms that did and did not receive phytoremediation treatment and the control microcosms. Study results have indicated that TNT phytoremediation via artificial wetlands not only may clean up hazardous waste at munitions sites but also may encourage the growth of aquatic populations such as rotifers.

Predictors of 90-day outcome in patients stabilized after acute coronary syndromes

AIMS

We investigated predictors of 90-day risk among patients surviving the early period after an acute coronary syndrome (ACS).

METHODS AND RESULTS

The study population included 15 904 stabilized ST-segment elevation or non-ST-segment elevation ACS patients randomized in SYMPHONY and 2nd SYMPHONY. We developed risk models for death, death or myocardial infarction (MI), and death, MI, or severe recurrent ischaemia (SRI) using Cox proportional-hazards techniques. Demographic, history, and pre-randomization clinical and medication variables were tested. Validation techniques included development of individual trial models, backward elimination and bootstrapping. Of 118 variables, 17 independently predicted mortality. The strongest associations included greater age (chi(2)=31.1), higher randomization heart rate (chi(2)=27.4), and heart failure (HF) variables (HF between qualifying event and randomization, chi(2)=21.8; history of HF, chi(2)=12.2). Higher creatinine clearance (chi(2)=17.7) and percutaneous coronary intervention between qualifying event and randomization (chi(2)=11.1) most strongly predicted lower risk. Similar characteristics entered the double and triple composite models, but HF variables and age less strongly predicted these end-points.

CONCLUSIONS

In patients stabilized after ACS, those at highest risk over the next 90 days can be identified. Typical clinical markers are better at identifying risk of death than non-fatal MI or SRI. Novel risk markers are needed for these outcomes.

Refinement of the nickel site structure in Desulfovibrio gigas hydrogenase using range-extended EXAFS spectroscopy

We have reexamined the Ni EXAFS of oxidized, inactive (as-isolated) and H(2) reduced Desulfovibrio gigas hydrogenase. Better spatial resolution was achieved by analyzing the data over a 50% wider k-range than was previously available. A lower k(min) was obtained using the FEFF code for phase shifts and amplitudes. A higher k(max) was obtained by removing an interfering Cu signal from the raw spectra using multiple energy fluorescence detection. The larger k-range allowed us to better resolve the Ni-S bond lengths and to define more accurately the Ni-O and Ni-Fe bond lengths. We find that as-isolated, hydrogenase has two Ni-S bonds at approximately 2.2 A, but also 1-2 Ni-S bonds in the 2.35+/-0.05 A range. A Ni-O interaction is evident at 1.91 A. The as-isolated Ni-Fe distance cannot be unambiguously determined. Upon H(2) reduction, two short Ni-S bonds persist at approximately 2.2 A, but the remaining Ni-S bonds lengthen to 2.47+/-0.05 A. Good simulations are obtained with a Ni-Fe distance at 2.52 A, in agreement with crystal structures of the reduced enzyme. Although not evident in the crystal structures, an improvement in the fit is obtained by inclusion of one Ni-O interaction at 2.03 A. Implications of these distances for the spin-state of H(2) reduced H(2)ase are discussed.

Skylab nutritional studies

Precise nutritional specifications arising from both physiological and experimental requirements necessitated a comprehensive study of the chemical composition of the Skylab food supply. Each of the approximately seventy different food items was analyzed for digestible and non-digestible carbohydrate, and for protein, amino acids, fat, fatty acids, vitamins and minerals. Menus were formulated to provide at least the National Research Council's Recommended Dietary Allowance of all essential nutrients and, in addition, to provide constant daily intakes of calcium, phosphorus, magnesium, sodium, potassium and protein. In general, the crew members adhered to their programmed menus. The ability to swallow and digest food was unaffected by prolonged weightlessness. Taste acuity also appeared to be undiminished in flight. The bone and muscle changes which occurred in previous flights were more pronounced in Skylab. It is concluded that these changes did not develop as a result of nutritional deficit. If such changes are nutritionally related, they point to the existence of nutritional requirements in weightlessness which differ quantitatively from those observed on earth.

Attention constraints of semantic activation during visual word recognition

The reduction of semantic priming following letter search of the prime suggests that semantic activation can be blocked if attention is allocated to the letter level during word processing. Is this true even for the very fast-acting component of semantic activation? To test this, the authors explored semantic priming of lexical decision at stimulus onset asynchronies (SOAs) of either 200 or 1,000 ms. Following semantic prime processing, priming occurred at both SOAs. In contrast, no priming occurred at the long SOA following letter-level processing. Of greatest interest, at the short SOA there was priming following the less demanding consonant/vowel task but not following the more attention-demanding letter search task. Hence, semantic activation can occur even when attention is directed to the letter level, provided there are sufficient resources to support this activation. The authors conclude that the default setting during word recognition is for fast-acting activation of the semantic system.

Hypertension in hemodialysis patients

Hypertension is very common and often poorly controlled in patients undergoing chronic hemodialysis. While high blood pressure has been documented to adversely impact several intermediate outcomes of cardiovascular disease, whether hypertension is an independent risk factor for mortality in this population is not clear. Expansion of extracellular fluid volume is the major pathophysiologic mechanism for the development of hypertension in these patients; however, alterations in other humoral mechanisms also play a significant role. Optimization of volume status is, therefore, the cornerstone of therapy with additional use of antihypertensive medications as needed. Good quality prospective studies are urgently needed to define the measurement techniques and blood pressure goals, and to develop therapeutic strategies for more effective management of hypertension in this high-risk population.

Attention constraints of semantic activation during visual word recognition

The reduction of semantic priming following letter search of the prime suggests that semantic activation can be blocked if attention is allocated to the letter level during word processing. Is this true even for the very fast-acting component of semantic activation? To test this, the authors explored semantic priming of lexical decision at stimulus onset asynchronies (SOAs) of either 200 or 1,000 ms. Following semantic prime processing, priming occurred at both SOAs. In contrast, no priming occurred at the long SOA following letter-level processing. Of greatest interest, at the short SOA there was priming following the less demanding consonant/vowel task but not following the more attention-demanding letter search task. Hence, semantic activation can occur even when attention is directed to the letter level, provided there are sufficient resources to support this activation. The authors conclude that the default setting during word recognition is for fast-acting activation of the semantic system.

Identification of Streptococcus pneumoniae revisited

The sensitivities and specificities of several different diagnostic assays for Streptococcus pneumoniae were assessed using 99 clinical isolates of S. pneumoniae and 101 viridans streptococci and were as follows: Pneumoslide, 99 and 87%, respectively; Directigen, 100 and 85%, respectively; Phadebact, 100 and 98%, respectively; deoxycholate drop test, 99 and 98%, respectively; deoxycholate tube test, 100 and 99%, respectively; optochin, 99 and 98%, respectively; and Gram Positive Identification Card, 90 and 96%, respectively. Identification of clinical isolates of S. pneumoniae should be confirmed using one or more diagnostic assays with well-documented high (e.g., > or =95%) sensitivities and specificities.

1H-Pyrrole-2-carbothioamide

The reaction of ethoxycarbonylpyrrole-2-thiocarboxamide with sodium hydroxide affords the known title compound, C(5)H(6)N(2)S, whose structure shows a three-dimensional hydrogen-bonded lattice.

Glycosylation of a Streptomyces coelicolor A3(2) cell envelope protein is required for infection by bacteriophage phi C31

Mutants of Streptomyces coelicolor A3(2) J1929 (Delta pglY) were isolated that were resistant to the Streptomyces temperate phage phi C31. These strains could be transfected with phi C31 DNA, but could not act as infective centres after exposure to phage. Thus, it was concluded that infection was blocked at the adsorption/DNA injection step. The mutants fell into three classes. Class I mutants were complemented by a gene, SCE87.05, isolated from the cosmid library of S. coelicolor A3(2). The product of SCE87.05 had good overall homology to a Mycobacterium tuberculosis hypothetical protein and regions with similarity to dolichol phosphate-D-mannose:protein O-D-mannosyltransferases. Concanavalin A (ConA) inhibited phi C31 infection of S. coelicolor J1929, and this could be partially reversed by the addition of the sugar, alpha-D-methyl-pyranoside. Moreover, glycosylated proteins from J1929, but not from the class I mutant DT1017, were detected using ConA as a probe in Western blots. Class I and II mutants were sensitive to phi C31hc, a previously isolated phage exhibiting an extended host range phenotype, conferred by h. A phage with the same phenotype, phi DT4002, was isolated independently, and a missense mutation was found in a putative tail gene. It is proposed that the phi C31 receptor is a cell wall glycoprotein, and that the phi C31h mutation compensates for the lack of glycosylation of the receptor.

Decision points in the integrative research review process: a flow-chart approach

With the ever increasing volume of research information appearing in the literature, research syntheses are becoming more popular among researchers in various disciplines. This phenomenon demands application of rigorous and systematic review methodologies. Using Cooper's five-stage process for conducting an integrative research review, the authors have constructed a flow chart for health sciences librarians and others using this approach to identify decision points in this process. The accompanying narrative details the information that must be considered and analyzed. Included in the flow chart and text is an elaboration of meta-analysis and an integrative review to accommodate both quantitative and qualitative research results. A case is made for a collaborative relationship between the researcher and the librarian.

Modulating semantic feedback in visual word recognition

According to the interactive activation framework proposed by McClelland and Rumelhart (1981), activation spreads both forward and backward between some levels of representation during visual word recognition. An important boundary condition, however, is that the spread of activation from lower to higher levels can be prevented (e.g., explicit letter processing during prime processing eliminates the well-documented semantic priming effect). Can the spread of activation from higher to lower levels also be prevented? This question was addressed with a choice task procedure in which subjects read a prime word and then responded to a target, performing either lexical decision or letter search depending on the color of the target. A semantic context effect was observed in lexical decision, providing evidence of semantic-level activation. In contrast, there was no semantic context effect in the letter search task, despite evidence of lexical involvement: Words were searched faster than nonwords. Further evidence of lexical involvement in the letter search task appeared in Experiment 2 in the form of greater identity priming for words than for nonwords. The results of these experiments are consistent with the conclusion that feedback from the semantic level to the lexical level can be blocked. Hence, between-level activation blocks can be instantiated in both bottom-up and top-down directions.

'See and treat' at colposcopy--achieving the standard

The National Health Service Cervical Screening Programme has issued quality standards for the colposcopy service nationally. One standard is that for women who undergo treatment at their first colposcopy clinic visit, 90% should have proven cervical intra-epithelial neoplasia (CIN) on histology. We have assessed data from a teaching hospital colposcopy clinic over a 9-year period to assess the criteria that should be satisfied in order to achieve this target. We propose that only those women with severe dyskaryosis on the referral smear and a colposcopic appearance of CIN 2 or 3, or those in whom the colposcopic appearance suggests CIN 3 with any grade of dyskaryosis undergo treatment at their first visit.

Stories of lesbian in/visibility in nursing

In this article, a study of the life histories of 5 self-identified lesbian women in nursing is reported. A metastory of "In/Visibility" captured the essence of lesbians being the focus of intense scrutiny while at the same time feeling the pressure to keep their lifestyle and identity hidden from others. Seven story themes were elaborated: closeting of lesbianism in nursing, isolating and hiding from self and others, living a double-life, self-loathing and shame, experiencing discrimination from others, keeping safe, and threatening others who are closeted.

Control of directionality in the site-specific recombination system of the Streptomyces phage phiC31

The genome of the Streptomyces temperate phage phiC31 integrates into the host chromosome via a recombinase belonging to a novel group of phage integrases related to the resolvase/invertase enzymes. Previously, it was demonstrated that, in an in vitro recombination assay, phiC31 integrase catalyses integration (attP/attB recombination) but not excision (attL/attR). The mechanism responsible for this recombination site selectivity was therefore investigated. Purified integrase was shown to bind with similar apparent binding affinities to between 46 bp and 54 bp of DNA at each of the attachment sites, attP, attB, attL and attR. Assays using recombination sites of 50 bp and 51 bp for attP and attB, respectively, showed that these fragments were functional in attP/attB recombination and maintained strict site selectivity, i.e. no recombination between non-permissive sites, such as attP/attP, attB/attL, etc., was observed. Using bandshifts and supershift assays in which permissive and non-permissive combinations of att sites were used in the presence of integrase, only the attP/attB combination could generate supershifts. Recombination products were isolated from the supershifted complexes. It was concluded that these supershifted complexes contained the recombination synapse and that site specificity, and therefore directionality, is determined at the level of stable synapse formation.

OctreoTher: ongoing early clinical development of a somatostatin-receptor-targeted radionuclide antineoplastic therapy

OctreoTher ((90)Y-DOTA-D-Phe(1)-Tyr(3)-octreotide, a.k.a. (90)Y-SMT 487) consists of a somatostatin peptide analogue (Tyr(3)-octreotide), coupled with a complexing moiety (DOTA), and labeled with a tightly bound beta-emitter (yttrium-90). By targeting somatostatin receptor-positive tumors (as imaged by OctreaScan it may deliver a tumoricidal dose of radiation. Phase I clinical trials, conducted in patients with neuroendocrine tumors, established the safety and tolerability of the dose selected for further study and demonstrated the capacity of OctreoTher to deliver radiation doses to tumors that resulted in significant neuroendocrine tumor shrinkage. Novartis-sponsored phase II studies will soon begin to test the efficacy of OctreoTher in breast and small cell lung cancer. A fixed-dose regimen of 120 mCi/cycle x 3 cycles administered with concomitant amino acid infusion has been chosen for the study. Phase I data and published literature support that this fixed dose regimen will be safely tolerated.

Cross-sectional study of the association of abomasal displacement or volvulus with serum electrolyte and mineral concentrations in dairy cows

The objective of this study was to evaluate serum mineral and electrolyte concentrations at the time of on-farm diagnosis of left displaced abomasum, right displaced abomasum, or abomasal volvulus in dairy cows. Data were collected from 104 affected cows and 96 control cows matched with cases, based on herd, parity, and stage of lactation. Cows with abomasal displacement or volvulus had significantly lower calcium, phosphorous, magnesium, potassium, and chloride concentrations and increased anion gap at the time of diagnosis compared with control cows from the same herds. The percentages of cases and controls with total serum calcium concentrations below the lower limit of the laboratory reference range (2.08 mmol/L [8.3 mg/dL]) were 70% and 23%, respectively. Based on the large percentage of cases with hypocalcemia, administering calcium salts at the time of treatment of field cases of abomasal displacement or volvulus may be beneficial.

On the interaction between linguistic and pictorial systems in the absence of semantic mediation: evidence from a priming paradigm

Use of the letter search task in the context of the priming paradigm has proved to be an invaluable tool for the investigation of the strategic control of processes involved in word recognition. In particular, previous findings that letter search on a prime word interferes with the priming of semantically/associatively related targets, but not with the priming of either identical or morphologically related targets, suggests that letter search may selectively interfere with semantic processing, leaving other levels of processing intact. In the present experiments, this investigation was extended by exploring the priming of pictures following letter search of either a same-concept word (repetition priming) or a semantically/associatively related word (semantic priming). There was significant repetition priming of picture categorization following both silent reading and letter search of the prime word (Experiments 1 and 2). In contrast, semantic priming of pictures was found only following silent reading of the prime; there was no semantic priming following letter search of the prime (Experiment 2). This pattern of results suggests that focusing attention at the letter level during prime processing selectively attenuates activation of the semantic system by the prime. It does not prevent the spread of activation between the lexical and pictogen levels of representation of a given concept.

Interdialytic weight gain, compliance with dialysis regimen, and age are independent predictors of blood pressure in hemodialysis patients

Hypertension is a common problem in patients undergoing chronic hemodialysis. The purpose of this study is to identify the clinical and demographic factors independently associated with blood pressure in this population. Data collected for the Dialysis Morbidity and Mortality Study Wave 1 by the US Renal Data System were analyzed. The mean predialysis blood pressure for this cohort of 5,369 patients was 149/79 mm Hg. Sixty-three percent of the patients were hypertensive; 27%, 25%, and 11% had stages 1, 2, and 3 hypertension, respectively. Young age, black race, male sex, diabetes as cause of end-stage renal disease, erythropoietin therapy, and smoking were associated with higher blood pressure in the univariate analysis. Patients skipping or shortening one or more dialysis treatments had higher blood pressure. The presence of congestive heart failure and coronary heart disease was associated with lower blood pressure. On multivariate analysis, high interdialytic weight gain, noncompliance with dialysis regimen, and younger age were independent predictors of higher blood pressure. In summary, hypertension is common and poorly controlled in patients undergoing chronic hemodialysis. Greater interdialytic weight gain and noncompliance with dialysis regimen are independently associated with higher blood pressure, and advancing age is associated with lower blood pressure levels in this population. Therapeutic regimens emphasizing reduction of interdialytic weight gain and improved compliance with the dialysis regimen need to be evaluated for improving the management of hypertension. The effect of age and other comorbid conditions, particularly cardiovascular disease, must be considered while studying the relationship between blood pressure and mortality in patients undergoing chronic hemodialysis.

Magnetoencephalography in children with Landau-Kleffner syndrome and acquired epileptic aphasia

BACKGROUND AND PURPOSE

Landau-Kleffner syndrome (LKS) is epileptiform aphasia acquired during childhood and occurring in children with previously normal language development. The epileptiform activity in these children is thought to result in a functional ablation of eloquent speech areas. The purpose of this study was to investigate the usefulness of magnetoencephalography (MEG) for localizing the source of epileptiform activity in these patients.

METHODS

Nineteen patients with acquired aphasia and a suspected diagnosis of LKS were referred for MEG evaluation. Patients ranged in age from 4 to 14 years. Fourteen MEG studies were performed on a 74-channel system, four on a 148-channel whole-head system, and one on a 37-channel system.

RESULTS

Thirteen of the 19 patients had perisylvian MEG spikes. In 10 of the patients, the spikes were bilateral, and in three they were unilateral. Four other patients had non-sylvian spikes, and two patients had no spikes recorded. The results of MR imaging were normal or noncontributory for all 19 patients.

CONCLUSIONS

MEG can play a useful role in evaluating children with LKS and acquired epileptiform aphasia, both in diagnosis and in aiding presurgical localization of epileptiform activity when surgery is being considered.

Effects of the nonpeptide V(1) vasopressin receptor antagonist SR49059 in hypertensive patients

We assessed the clinical and pharmacological profile of the orally active V(1) vascular vasopressin (AVP) receptor nonpeptide antagonist SR49059 (SR) during the osmotic stimulation of AVP release in hypertensive patients. In a double-blind crossover-versus-placebo study, 24 untreated stage I or II essential hypertensive patients (12 whites and 12 blacks) received a single 300 mg oral dose of SR 2 hours before the stimulation of AVP secretion with a 5% hypertonic saline infusion. Hemodynamic, humoral, and hormonal parameters were monitored for up to 28 hours after drug administration. SR did not alter blood pressure or heart rate before the saline infusion and did not reduce the blood pressure increment induced by the hypertonic saline infusion. However, the blood pressure peak at the end of the hypertonic saline infusion was slightly lower in the presence of SR (P=0.04). Heart rate was significantly faster between 4 and 6 hours after SR administration (P=0.02). The rise in plasma sodium and osmolality triggered by the saline infusion was not modified by SR, but AVP release was slightly greater in the presence of SR (P<0.0003). AVP-induced aggregation of blood platelets in vitro was significantly reduced by SR, with a peak effect 2 hours after drug administration that coincided with the SR peak plasma concentration. Plasma renin activity and aldosterone before and after the saline infusion were not modified by SR. Urine volume and osmolality were not altered by SR administration. SR effects were similar in the 2 ethnic groups as well as in salt-sensitive versus salt-resistant patients. In a situation of AVP osmotic release and volume expansion in hypertensive patients, a single oral dose of the V(1) vascular AVP receptor nonpeptide antagonist SR49059, which is able to block AVP-induced platelet aggregation, exerts a transient vasodilation effect that is not associated with a sustained blood pressure reduction. SR49059 is a pure V(1) vascular receptor antagonist that is devoid of V(2) renal receptor actions.

Benefits of massage therapy for hospitalized patients: a descriptive and qualitative evaluation

CONTEXT

Some acute and long-term care facilities are instituting massage therapy programs to support their patients' health, healing, and quality of life. Evaluation of the impact of these programs from the perspective of patients, providers, and therapists is important for administrative decision making and the design of future outcomes research.

OBJECTIVE

To uncover and elucidate a range of patient outcomes of a therapeutic massage program within an acute care setting.

DESIGN

Descriptive and qualitative evaluation. Surveys and narrative reports were completed by 70 patients, 14 healthcare providers, and 4 massage therapists.

SETTING

A large university hospital.

PATIENTS

113 hospitalized patients received 1 to 4 massages during the course of their hospital stay.

INTERVENTION

Massage therapy.

MAIN OUTCOME MEASURES

Narrative data were coded into 8 categories (pain, sleep, tension/anxiety, body awareness, physical functioning, psychological support, enhancing healing, and value). Selected patient responses were included to elaborate the meanings of these categories.

RESULTS

The most frequently identified outcomes were increased relaxation (98%), a sense of well-being (93%), and positive mood change (88%). More than two thirds of patients attributed enhanced mobility, greater energy, increased participation in treatment, and faster recovery to massage therapy. Thirty-five percent stated that benefits lasted more than 1 day.

CONCLUSIONS

The study supported the value of this hospital-based massage therapy program and uncovered a range of benefits of massage therapy for hospitalized patients that should be studied further.