cssi/SciSciGPT-SciSciNet huggingface dataset:
TH‐E‐17A‐04: Geometric Validation of K‐Space Self‐Gated 4D‐MRI Vs. 4D‐CT Using A Respiratory Motion Phantom

Purpose: 4D-CT is often limited by motion artifacts, low temporal resolution, and poor phase-based target definition. We recently developed a novel k-space self-gated 4D-MRI technique with high spatial and temporal resolution. The goal here is to geometrically validate 4D-MRI using a MRI-CT compatible respiratory motion phantom and comparison to 4D-CT. Methods: 4D-MRI was acquired using 3T spoiled gradient echo-based 3D projection sequences. Respiratory phases were resolved using self-gated k-space lines as the motion surrogate. Images were reconstructed into 10 temporal bins with 1.56×1.56×1.56mm3. A MRI-CT compatible phantom was designed with a 23mm diameter ball target filled with highconcentration gadolinium(Gd) gel embedded in a 35×40×63mm3 plastic box stabilized with low-concentration Gd gel. The whole phantom was driven by an air pump. Human respiratory motion was mimicked using the controller from a commercial dynamic phantom (RSD). Four breathing settings (rates/depths: 10s/20mm, 6s/15mm, 4s/10mm, 3s/7mm) were scanned with 4D-MRI and 4D-CT (slice thickness 1.25mm). Motion ground-truth was obtained from input signals and real-time video recordings. Reconstructed images were imported into Eclipse(Varian) for target contouring. Volumes and target positions were compared with ground-truth. Initial human study was investigated on a liver patient. Results: 4D-MRI and 4D-CT scans for the different breathing cycles were reconstructedmore » with 10 phases. Target volume in each phase was measured for both 4D-CT and 4D-MRI. Volume percentage difference for the 6.37ml target ranged from 6.67±5.33 to 11.63±5.57 for 4D-CT and from 1.47±0.52 to 2.12±1.60 for 4D-MRI. The Mann-Whitney U-test shows the 4D-MRI is significantly superior to 4D-CT (p=0.021) for phase-based target definition. Centroid motion error ranges were 1.35–1.25mm (4D-CT), and 0.31–0.12mm (4D-MRI). Conclusion: The k-space self-gated 4D-MRI we recently developed can accurately determine phase-based target volume while avoiding typical motion artifacts found in 4D-CT, and is being further studied for use in GI targeting and motion management. This work supported in part by grant 1R03CA173273-01.« less
How genetically heterogeneous are the major psychiatric disorders

Linking specific chromosomal regions with the abnormal genes responsible for major psychiatric disorders is rendered particularly difficult because of three factors: diagnostic uncertainty; the possibility that some psychiatric disorders are caused by the concerted action of more than one gene; and the possibility that similar disorders may result from alternative genetic abnormalities. The approach proposed here is to concentrate initially on the highly focused problem of resolving the question of genetic heterogeneity of a given disorder. To this end, it is recommended (a) that studies concentrate on pedigrees large enough to contain at least two nuclear families with several affected individuals, and (b) that, within them, work be confined to an intensive examination of such small nuclear families containing an affected parent and at least two affected offspring with a fairly unmistakable phenotype--bipolar disorder, type I. By using molecular and genetic techniques designed to extract maximal information from this relatively small number of affected individuals, it should be possible to determine whether or not bipolar disorder is genetically heterogeneous. This is a limited but very important question, and the technology is presently available to answer it. The answer should, in turn, guide subsequent approaches to identification of the relevant gene or genes.
Partial Reversion in Yeast: Genetic Evidence for a New Type of Bifunctional Protein

Two kinds of phenotypic expression in purine biosynthesis result from recessive mutation to adel2 in baker's yeast. The mutants are adenine-specific, blocked in the conversion of inosine 5'-phosphate to adenylosuccinic acid; their response to inhibition of pathway activity by adenine is considerably reduced. Allelic partial reversions can restore prototrophy without correcting the regulatory defect imparted by the primary mutation. The separation of the two properties of the locus by allelic mutation supports the hypothesis that the locus specifies a protein of two independent functions, enzymatic and regulatory.
Colorimetric determination of adenine in plant tissues.

Abstract Details of a colorimetric method developed for quantitative adenine determination in plant tissues are given. The critical steps in the procedure are discussed. The method gives consistent recovery of adenine added to etiolated pea tissue. Results of analyses of etiolated pea plants and tobacco plants are given.
The Ability of Polyphenols to Reduce Aβ-Induced Apoptosis Associated with Alzheimer's Disease

Alzheimer's disease (AD), the most common form of dementia, is characterized by extracellular plaques in the brain created when monomeric amyloid-β (Aβ) protein aggregates into fibrillar structures. Soluble Aβ aggregates, including oligomers that form along the reaction pathway, are believed to be the more toxic species and can increase the production of reactive oxygen species (ROS). Polyphenols have been suggested as a complimentary AD therapeutic based on epidemiological evidence that polyphenol-rich diets correlate with a reduced incidence of AD. In particular, many flavonoids, a subclass of polyphenols, have the ability to inhibit Aβ aggregation. Alternatively, polyphenols can counter Aβ-induced cellular responses by neutralizing ROS through their antioxidant properties. This study sought to identify polyphenols that can reduce Aβ-induced apoptosis by inhibiting Aβ aggregation and/or reducing ROS.Polyphenols investigated include quercetin (QUE), rhamnetin (RHA), isorhamnetin (IRHA), and tamarixetin (TAM). Using SDS-PAGE and Western blot to evaluate oligomer size, only IRHA was unable to reduce Aβ oligomers 250 – 100 kDa in size, while QUE reduced these oligomers by 88.3 ± 2.4%. All compounds reduced Aβ oligomers <100 kDa in size, although IRHA was still the weakest inhibitor. Antioxidant capabilities were quantified in vitro relative to Trolox, a vitamin E analog. All compounds tested exhibited antioxidant capability similar to Trolox. To assess the effect of anti-aggregation and antioxidant properties on Aβ-induced apoptosis, human neuroblastoma cells were stained using TUNEL, which identifies breaks in the DNA strand. Polyphenols with anti-aggregation properties successfully reduced apoptosis, and it is hypothesized that antioxidant activity will also have a protective effect.
A Cell's Sense of Direction

In eukaryotic cells directional sensing is mediated by heterotrimeric guanine nucleotide-binding protein (G protein)-linked signaling pathways. In Dictyostelium discoideum amoebae and mammalian leukocytes, the receptors and G-protein subunits are uniformly distributed around the cell perimeter. Chemoattractants induce the transient appearance of binding sites for several pleckstrin homology domain-containing proteins on the inner face of the membrane. In gradients of attractant these sites are persistently present on the side of the cell facing the higher concentration, even in the absence of a functional actin cytoskeleton or cell movement. Thus, the cell senses direction by spatially regulating the activity of the signal transduction pathway.
Activation of a Gq-coupled membrane estrogen receptor rapidly attenuates α2-adrenoceptor-induced antinociception via an ERK I/II-dependent, non-genomic mechanism in the female rat.

Abstract Though sex differences in pain and analgesia are known, underlying mechanisms remain elusive. This study addresses the selective contribution of membrane estrogen receptors (mERs) and mER-initiated non-genomic signaling mechanisms in our previously reported estrogen-induced attenuation of α2-adrenoceptor-mediated antinociception. By selectively targeting spinal mERs in ovariectomized female rats using β-estradiol 6-(O-carboxy-methyl)oxime bovine serum albumin (E2BSA) (membrane impermeant estradiol analog), and ERα selective agonist 4,4′,4″-(4-propyl-[1H]-pyrazole-1,3,5-triyl)trisphenol (PPT), ERβ selective agonist 2,3-bis(4-hydroxyphenyl)-propionitrile (DPN), G-protein-coupled estrogen receptor 30 (GPR30) agonist G1 and Gq-coupled mER (Gq-mER) agonist STX, we provide strong evidence that Gq-mER activation may solely contribute to suppressing clonidine (an α2-adrenoceptor agonist)-induced antinociception, using the nociceptive tail-flick test. Increased tail-flick latencies (TFLs) by intrathecal (i.t.) clonidine were not significantly altered by i.t. PPT, DPN, or G1. In contrast, E2BSA or STX rapidly and dose-dependently attenuated clonidine-induced increase in TFL. ICI 182,780, the ER antagonist, blocked this effect. Consistent with findings with the lack of effect of ERα and ERβ agonists that modulate receptor-regulated transcription, inhibition of de novo protein synthesis using anisomycin also failed to alter the effect of E2BSA or STX, arguing against a contribution of genomic mechanisms. Immunoblotting of spinal tissue revealed that mER activation increased levels of phosphorylated extracellular signal-regulated kinase (ERK) but not of protein kinase A (PKA) or C (PKC). In vivo inhibition of ERK with U0126 blocked the effect of STX and restored clonidine antinociception. Although estrogen-induced delayed genomic mechanisms may still exist, data presented here indicate that Gq-mER may solely mediate estradiol-induced attenuation of clonidine antinociception via a rapid, reversible, and ERK-dependent, non-genomic mechanism, suggesting that Gq-mER blockade might provide improved analgesia in females.
Diet, consumption, and growth of juvenile fringed flounder (Etropus crossotus) ; a test of the 'maximum growth/optimum food hypothesis' in a subtropical nursery area

Recent somatic growth of juvenile fringed flounder (Etropus crossotus) collected in North Inlet (South Carolina, USA) was determined based on the width of the 24 most recently deposited daily increments in sagittal otoliths. Growth rates were estimated using previously published data on the experimentally validated relationship between the daily increment width and the somatic growth. A comparison of the realised growth with experimental data indicated that growth rates in the field were near optimum values determined under ad libitum food conditions. Gut contents analysis of field collected fringed flounder indicated that food consisted predominantly of zooplankton and motile epibenthic prey with calanoid copepods, in particular Pseudodiaptomus coronatus, as the most important food items. There was no clear ontogenetic shift in prey with increasing fish size. Copepods and their eggs remained a significant prey item in even the largest fish examined (>9 cm SL), while larger prey items like polychaete worms, cumaceans, bivalves, and mysids were found in the stomachs of smaller fish. The prey organisms were abundantly available during the period of highest settlement (May through September). Growth rates, biomass, consumption estimates, and prey availability in North Inlet indicated that growth of juvenile fringed flounder is not limited by food, but predominantly determined by water temperature. During the summer months temperature and food supply in North Inlet are near optimal for juvenile fringed flounder. This allows this short-lived species to grow rapidly to attain a mature size and migrate to near-shore waters to reproduce within one growing season.
On the augmented data manipulator network in SIMD environments

Formulas for the number of the augmented-data-manipulator (ADM)-passable permutations were given previously as cross-recurrence relations for the cardinalities of three specific subsets of such permutations. More concise, transparent recurrence formulas are derived utilizing a novel and conceptually simple model of the ADM. As a byproduct, a global control algorithm for the inverse ADM (IADM) is obtained that can set paths for all the IADM-passable permutations. This algorithm can be adapted for the ADM. Also included are two local control algorithms for the IADM/ADM: the signed bit difference tag control and the destination tag control. >
BEST PRACTICES: Syllabus Construction With a Commitment to Shared Governance

(2006). BEST PRACTICES: Syllabus Construction With a Commitment to Shared Governance. The Journal of Continuing Higher Education: Vol. 54, No. 1, pp. 20-27.
Spaces within spaces: rat parietal cortex neurons register position across three reference frames

We recorded parietal cortex neurons as rats traversed squared spiral tracks. Spatial firing patterns distinguished the behaviorally identical track segments composing loops, yet recurred with increasing or decreasing amplitude across the five loops composing the full track. These results indicate that parietal cortex neurons simultaneously respond to spatial relationships in multiple external reference frames, a phenomenon that may reflect a neural mechanism for relating parts to a whole.
Loss of the DEK-CAN fusion transcript in a child with t(6;9) acute myeloid leukemia following chemotherapy and allogeneic bone marrow transplantation

The AML1 gene on chromosome 21 is disrupted in the (8;21)(q22;q22) and (3;21)(q26;q22) translocations associated with myelogenous leukemias and encodes a DNA-binding protein. From AML1 gene, two representative forms of proteins, AML1a and AmL1b, are produced by an alternative splicing. Both forms have DNA-binding domain, but AmL1a lacks a putative transcriptional activation domain which AmL1b has. Here we demonstrate that AML1a, which solely has no effects as a transcriptional regulator, dominantly suppresses transcriptional activation by AML1b, and that AmL1a exhibits the higher affinity for DNA-binding than AML1b. Furthermore a dominant negative form of AML1, AML1a, totally suppressed granulocytic differentiation otherwise induced by granulocyte colony-stimulating factor when AML1a was overexpressed in 32Dc13 murine myeloid cells. Such differentiation block by AML1a was canceled by the concomitant overexpression of AmL1b. These data strongly suggest that a transcriptionally active form of AML1 is essential for the myeloid cell differentiation. In addition, we observed an altered expression level of AML1 along with the myeloid differentiation in several hemopoietic cell lines. In these cases, at least, the AML1 expression level is a potential regulator for myeloid cell differentiation.
The proximity of Mercury's spin to Cassini state 1 from adiabatic invariance

Abstract In determining Mercury's core structure from its rotational properties, the value of the normalized moment of inertia, C / M R 2 , from the location of Cassini 1 is crucial. If Mercury's spin axis occupies Cassini state 1, its position defines the location of the state, where the axis is fixed in the frame precessing with the orbit. Although tidal and core-mantle dissipation drive the spin to the Cassini state with a time scale O ( 10 5 ) years, the spin might still be displaced from the Cassini state if the variations in the orbital elements induced by planetary perturbations, which change the position of the Cassini state, cause the spin to lag behind as it attempts to follow the state. After being brought to the state by dissipative processes, the spin axis is expected to follow the Cassini state for orbit variations with time scales long compared to the 1000 year precession period of the spin about the Cassini state because the solid angle swept out by the spin axis as it precesses is an adiabatic invariant. Short period variations in the orbital elements of small amplitude should cause displacements that are commensurate with the amplitudes of the short period terms. The exception would be if there are forcing terms in the perturbations that are nearly resonant with the 1000 year precession period. The precision of the radar and eventual spacecraft measurements of the position of Mercury's spin axis warrants a check on the likely proximity of the spin axis to the Cassini state. How confident should we be that the spin axis position defines the Cassini state sufficiently well for a precise determination of C / M R 2 ? By following simultaneously the spin position and the Cassini state position during long time scale orbital variations over past 3 million years [Quinn, T.R., Tremaine, S., Duncan, M., 1991. Astron. J. 101, 2287–2305] and short time scale variations for 20,000 years [JPL Ephemeris DE 408; Standish, E.M., private communication, 2005], we show that the spin axis will remain within one arcsec of the Cassini state after it is brought there by dissipative torques. In this process the spin is located in the orbit frame of reference, which in turn is referenced to the inertial ecliptic plane of J2000. There are no perturbations with periods resonant with the precession period that could cause large separations. We thus expect Mercury's spin to occupy Cassini state 1 well within the uncertainties for both radar and spacecraft measurements, with correspondingly tight constraints on C / M R 2 and the extent of Mercury's molten core. Two unlikely caveats for this conclusion are: (1) an excitation of a free spin precession by an unknown mechanism or (2) a displacement by a dissipative core mantle interaction that exceeds the measurement uncertainties.
Facial swelling and eosinophilia in a 44-year-old woman.

CHIEF COMPLAINT A 44-year-old woman was referred to our institution for evaluation of facial swelling and progressively increasing eosinophilia, which began 2 months before she was seen. The patient first noticed right-sided temple and periorbital angioedema 2 days after completing a 10-day course of cefuroxime (Ceftin, GlaxoSmithKline, Research Triangle Park, NC) for a presumed upper respiratory infection/flulike illness. A complete blood count done 4 days after cefuroxime treatment was completed revealed an eosinophil count of 1,384 cells/mm3. The patient was then evaluated by an otolaryngologist and treated with a methylprednisolone acetate (Medrol Dose Pak Pharmacia, Peapack, NJ) and cetirizine hydrochloride (Zyrtec, Pfizer, New York, NY), which resulted in complete resolution of swelling. Angioedema recurred 2 days after she completed the methylprednisolone course (GlaxoSmithKline, Research Triangle Park, NC). Because of recurrent symptoms, she was started on zafirlukast (Accolate, AstraZeneca, Wilmington, DE) 20 mg twice a day and ranitidine (Zantac, GlaxoSmithKline) 75 mg twice a day. Angioedema persisted. Two weeks before the patient was seen in our institution, her eosinophil count increased to 5,742 cells/mm3. At that time, she was given a second methylprednisolone course. The angioedema again resolved completely and then recurred several days after methylprednisolone was completed. Two days before we saw her, her eosinophil count increased further to 13,050 cells/mm3. The patient was seen at our institution complaining of facial and upper extremity swelling, a 16-pound weight gain over the past 2 months, fatigue, and a nonpruritic rash on bilateral antecubital fossae for the past 2 to 3 days. She denied any headaches, shortness of breath, chest tightness, abdominal pain, bloody stools, lower extremity edema, or numbness/tingling in any extremities. MEDICAL HISTORY The patient had a history of osteoarthritis and mild mitral regurgitation. Surgical history was significant for breast biopsy of a benign tumor 6 years before and a total abdominal hysterectomy and bilateral oopherectomy 3 months before she was seen. She experienced allergy to penicillin 1.5 years earlier, which manifested as self-limited hives. There was no history of asthma, urticaria, food allergy, or recurrent respiratory infection.
Low-level steady-state auditory evoked potentials: effects of rate and sedation on detectability

Steady-state auditory evoked potentials (SSAEPs) in alert adults are most detectable at stimulus or modulation rates of about 40 Hz. Sedation reduces the detectability of 40-Hz SSAEPs and increases it for higher rate SSAEPs. This study examined whether rates higher than 40 Hz would be preferable for detecting responses to low-intensity tones in sedated adults. Fourteen normal adults listened to 640-Hz tones at modulation rates (and toneburst rates) of 20–160 Hz, in 10-Hz steps, at levels of 38 and 58 dB peak equivalent sound-pressure level (peSPL) (20 and 40 dB normal hearing level (nHL) for amplitude-modulated (AM) tones), both alert and sedated (1–2 g chloral hydrate). Sedation reduced both signal (SSAEP) power and noise power at all rates, but noise power reduction was greater for higher rates. Detectability in the alert condition was always greatest at 40 Hz. Under sedation, a second detectability peak was present at 90 Hz for 58-dB peSPL tones, approximately equal to that seen at 40 Hz. At 38 dB peSPL (sedated), peak detectability moved from 40 to 50 Hz. These results suggest that presentation/modulation rates around 40 Hz may be optimal for SSAEP detectability at low levels in adults, whether alert or sedated.
Photodisintegration of the Deuteron by Meson Reabsorption

A calculation is made of the photodisintegration of the deuteron which is caused by a meson being photo-produced on one of the nucleons of the deuteron and then subsequently being reabsorbed by the two nucleons. The measured photomeson production cross sections in hydrogen are separated into $S$-wave and $P$-wave parts so that the production of mesons on the neutron can be computed. The probability of meson reabsorption after production is taken as 0.11; this value results from Austern's calculation of the effects of $P$-state mesons. The effect of virtual production and reabsorption of $S$-state mesons even below the meson threshold is shown to be very important. Calculated values of the total cross section agree rather well with the experimentally measured cross sections.
Cell hybrid analysis of the presence of G1 in early and late passage 'lung' and 'liver' cells.

Abstract Previous studies have shown that when different naturally occurring cells that display a measurable G1 during logarithmic growth (G1 + cells) were hybridized, the resulting hybrids often lacked G1 (G1 − cells). This has been termed complementation. Four established G1 + lines of Chinese hamster were found to define three G1 + complementation groups. Three of these lines have been hybridized with early and late passage fibroblast-like cells from the lung and liver of a Chinese hamster newborn. The complementation tests indicate: 1. 1. that the basis for the expression of G1 of the ‘lung’ cultures is different than that of the ‘liver’ cells 2. 2. that late passage (transformed) cells retain the same basis for G1 as their ‘ancestral’ early passage cells. These results show that presumably different cells can express G1 for different reasons, which in turn might be related to cellular differentiation.
Isolation of Ribosomes by Chromatography

Mixed-mode chromatography on cysteine-SulfoLink resin efficiently separates ribosomes from cell lysates and is particularly effective at rapidly removing endogenous proteases and nucleases, resulting in ribosomes of improved purity, integrity, and activity. Binding occurs partly by anion exchange of the RNA of the ribosomes, so that cells must be lysed in a buffer of moderate ionic strength (conductivity no more than 20 mS for chromatography of bacterial ribosomes) without any highly charged additives (e.g., heparin, which is used to inhibit RNases in yeast). A robust protocol for Escherichia coli is given here as an example.
Interatomic interactions in covalent and ionic solids

The total energy in tight-binding theory is obtained to second order in the ratio of the width of the bonding band to the bonding-antibonding splitting. This is the reciprocal of the expansion parameter appropriate to metals. No other important approximation on the minimal-basis, nearest-neighbor, tight-binding Hamiltonian is required for the periodic lattice. This leads to a simple theory of covalent bonding that is more accurate and much more general than bond-orbital methods. The lowest-order term is a bonding term that is a square root of a sum over neighbors performed at each atom. Writing the total bonding energy as a sum of such terms evaluated locally becomes an approximation in nonperiodic systems, but gives the total-energy estimate directly in terms of local interactions. The interesting second-order term, a chemical ``grip,'' is a sum over pairs of neighbors to each atom, depending upon the angle they subtend. A radial overlap repulsion of the form A/${\mathit{d}}^{3}$+B/${\mathit{d}}^{12}$ is added, and fitted to the observed equilibrium spacing and bulk modulus. The resulting form is used for a number of covalent systems to predict spacings and relative energies in competing structures. The bonding term always favors high coordination, but the grip, larger for small atoms and nonpolar systems, determines the tetrahedral structure for semiconductors and the graphite structure for carbon. An elastic shear constant in the tetrahedral structure is also obtained. The method generalizes directly to other systems such as transition-metal compounds and ${\mathrm{SiO}}_{2}$. It also gives directly short-ranged interatomic forces, which could be used in molecular dynamics.
Innervation of abdominal paraganglia: an ultrastructural study.

Abdominal extra-adrenal chromaffin tissue, or paraganglia, was examined at the ultrastructural level to elucidate the innervation of this adrenal medullary homologue. Paraganglia display unmyelinated nerve fibers surrounded by Schwann cell cytoplasm. These nerves are separated from the paraganglion Type I (granule-containing) cells by cytoplasmic projections of paraganglion Type II (satellite) cells. However, serial sections show that the nerves eventually make synaptic contact with the Type I cell. At the axon-chromaffin cell junction, only the outer aspect of the nerve is covered by the satellite cell. The presynaptic endings contain numerous synaptic vesicles, mitochondria and glycogen particles. The vesicles are predominantly of the clear-cored variety, but a few possess centers which are elecron opaque. The pre- and postsynaptic membranes are separated bya subsynaptic space and occasionally exhibit the membranal densities usually associated with synaptic areas. These ultrastructural studies establish definite evidence that abdominal paraganglion cells are innervated.
Primary Retroperitoneal Lymph Node Dissection in Patients With Clinical Stage IS Testis Cancer

Purpose: Initial management for clinical stage IS (persistently increased tumor markers) nonseminomatous germ cell tumor has evolved from primary retroperitoneal lymph node dissection to induction chemotherapy at most medical centers. We analyzed the outcome in patients treated with primary retroperitoneal lymph node dissection.Materials and Methods: We reviewed the charts of patients who underwent retroperitoneal lymph node dissection at Brigham and Women's Hospital, and Dana Farber Cancer Center from 1993 to 2008. All patients with clinical stage IS were identified and perioperative data were obtained.Results: A total of 280 patients who underwent retroperitoneal lymph node dissection were identified, of whom 24 identified with clinical stage IS underwent primary dissection. Median followup was 2.9 years. Histopathology revealed an embryonal carcinoma component in 24 orchiectomy specimens (100%) with associated teratoma in 15 (63%). Positive lymph nodes were identified at retroperitoneal lymph node diss...
Separation of the primary and secondary kinetic isotope effects at a reactive center using starting material reactivities. Application to the FeCl3-Catalyzed oxidation of CH bonds with tert-butyl hydroperoxide

Abstract A method is reported for the determination of both the primary and secondary kinetic isotope effects at a reactive center based on staring material reactivities. This allows the determination of the separate KIEs in reactions for which neither product analysis nor absolute rate measurements are applicable. The methodology is applied to the FeCl 3 -catalyzed oxidation of ethylbenzene with tert-butyl hydroperoxide, which exhibits both a primary isotope effect and a substantial secondary isotope effect.
Extracorporeal Membrane Oxygenation and Retransplantation in Lung Transplantation: An Analysis of the UNOS Registry

Background Despite limited organ availability, extracorporeal membrane oxygenation (ECMO) and retransplantation are becoming more commonplace.
Nicotine-induced changes of brain β-endorphin

Abstract A consensus has emerged that endogenous opioid peptides and their receptors play an important role in the psychoactive properties of nicotine. Although behavioral studies have shown that β-endorphin contributes to the rewarding and emotional effects of nicotine, whether the drug alters the function of brain endorphinergic neurons is not fully explored. These studies investigated the effect of acute, 1 mg/kg, sc, and chronic, daily injection of 1 mg/kg, sc, for 14 days, administration of free base nicotine on brain β-endorphin and its precursor proopiomelanocortin (POMC). Acute and chronic treatment with nicotine decreased β-endorphin content in hypothalamus, the principal site of β-endorphin producing neurons in the brain, and in the endorphinergic terminal fields in striatum and hippocampus. The acute effect of nicotine on β-endorphin was reversed by the nicotinic antagonist mecamylamine and the dopamine antagonist haloperidol, indicating pharmacological specificity and involvement of dopamine D2-like receptors. Similar observations were made in prefrontal cortex. POMC mRNA in hypothalamus and prefrontal cortex was unchanged following acute nicotine, but it decreased moderately with chronic treatment. The nicotine treatments had no effect on pituitary and plasma β-endorphin. Taken together, these results could be interpreted to indicate that nicotine alters the synthesis and release of β-endorphin in the limbic brain in vivo. Altered endorphinergic function may contribute to the behavioral effects of acute and chronic nicotine treatment and play a role in nicotine addiction.
The mid-trimester placenta previa: a prospective follow-up.

Abstract One hundred and fifty-six mid-trimester sonograms were performed at our prenatal diagnostic unit. Twenty women were found to have a low-lying placenta or placenta previa and were followed by serial ultrasound examinations to observe changes in placental position. Eighty percent of women, i.e., 16 20 , with a low-lying placenta had converted to normal implantation by the time of delivery. Most of the conversions had taken place at approx. 34 weeks of gestation. The patients with mid-trimester low-lying placenta had an increased risk of third-trimester bleeding, abruptio placentae and cesarean sections. The infants were also at risk of premature delivery. Patients with mid-trimester low-lying or placenta previa should be followed by ultrasound to monitor delivery.
Self-diffusion of alkylammonium ions in montmorillonite

Abstract Self-diffusion measurements of methyl, ethyl, n-propyl, trimethyl, and tetramethylammonium ions were made in montmorillonite pellets with increasing water content. Diffusion rates increased rapidly with the initial adsorption of water. Since porosity of the pellets remained essentially constant with addition of the first traces of water and there was no direct correlation between diffusion rates and structural expansion, it was concluded that the increase in diffusivity with water content is due largely to an interaction between the water and alkylammonium cations which probably results in a reorientation or unkeying of the cations from the silicate surface. Infrared studies indicate this water-cation interaction may be due to either hydrogen bonding or ion-dipole interaction depending on the alkylammonium cation involved. Size and shape of the alkylammonium ions have an effect on diffusion rates in the clay and were most evident at the higher water contents.
Efficient Implementations of the Quadrature-Free Discontinuous Galerkin Method

The efficiency of the quadrature-free form of the dis- continuous Galerkin method in two dimensions, and briefly in three dimensions, is examined. Most of the work for constant-coefficient, linear problems involves the volume and edge integrations, and the transformation of information from the volume to the edges. These operations can be viewed as matrix-vector multiplications. Many of the matrices are sparse as a result of symmetry, and blocking and specialized multiplication routines are used to account for the sparsity. By optimizing these operations, a 35% reduction in total CPU time is achieved. For nonlinear problems, the calculation of the flux becomes dominant because of the cost associated with polynomial products and inversion. This component of the work can be reduced by up to 75% when the products are approximated by truncating terms. Because the cost is high for nonlinear problems on general elements, it is suggested that simplified physics and the most efficient element types be used over most of the domain.
Epidemiology of burn injuries presenting to North Carolina emergency departments in 2006-2007.

Approximately 600,000 burns present to Emergency Departments each year in the United States, yet there is little systematic or evidence-based training of Emergency Physicians in acute burn management. We retrospectively accessed the North Carolina Disease Event Tracking and Epidemiologic Collection Tool (NC DETECT) database to identify all thermal burns and electrical injuries with associated thermal burns presenting to 92% of North Carolina Emergency Departments over a 1-year period. Results: 10,501 patients met inclusion criteria, 0.3% of all state-wide reported ED visits. Ninety-two percent of burn visits were managed exclusively by Emergency Physicians without acute intervention by burn specialists, including 87% of first degree, 82% of second degree, and 53% of third degree injuries. Only 4.3% were admitted; 4.3% were transferred to another institution. Fifty-five percent were male; 33% were aged 25–44 and 33% presented on weekends. Conclusion: This is the first state-wide study of burn injury and identifies Emergency Physicians as the major providers of acute burn care. Ninety-two percent of 10,501 burn visits, including the majority of severe injuries, were managed exclusively by Emergency Physicians. This supports a need for improved, evidence-based training of Emergency Physicians in the acute management of burns of all types.
The Nonoperative Treatment of Acute, Isolated (Partial or Complete) Posterior Cruciate Ligament-Deficient Knees: An Intermediate-term Follow-up Study

Fifty-seven consecutive patients (58 knees) with an acute, isolated, posterior cruciate ligament (PCL) injury were treated nonoperatively. Clinical, radiographic, and functional assessment was performed at a mean follow-up of 6.9 years (range 2 to 19.3 years) after the initial diagnosis. At the time of initial documentation of the injury, the posterior drawer test was grade A in 17 knees and grade B in 41 knees. The mean preinjury Tegner activity level was 7 (range 4 to 10). At latest follow-up, 38 knees had no pain, 14 had mild pain, and 6 had moderate pain on exertion. Fifty-four knees had no swelling, 3 had mild, intermittent swelling, and 1 had a moderate swelling on exertion. The posterior drawer test was grade A in 14 knees and grade B in 44 knees. The mean Lysholm-II knee score was 85.2 points (range 51 to 100 points) and the mean Tegner activity level was 6.6 (range 3 to 10). Based on Lysholm-II knee scoring system, the results were excellent in 23 knees (40%), good in 30 knees (52%), fair in 2 knees (3%), and poor in 3 knees (5%). No statistically significant correlation (p = 0.097) was seen between the grade of PCL laxity and Lysholm-II knee score. Plain radiographs showed mild (grade I) medial compartment osteoarthritis (OA) in 7 knees, and moderate (grade II) medial compartment OA in 3 knees. Mild patellofemoral OA was seen in 4 knees. We believe that most patients with acute, isolated PCL injuries do well with nonoperative treatment at a mean follow-up of 6.9 years. The level of evidence for this retrospective cohort study is level III.
Ocean chemistry during glacial time

Abstract Measurements of CO2 to air ratios in the gas trapped in bubbles in ice of glacial age suggest that the CO2 content of the atmosphere was considerably lower during peak glacial time than during Holocene time. The purpose of this paper is to show that such a change must in all likelihood be the result of alterations in the nutrient element chemistry of sea water. Two possible scenarios are presented. One involves alternate storage and erosion of phosphorous leaving residues from shelf sediments. The other involves changes in the C P ratio in the organic debris falling to the deep sea. Means of verifying the nutrient cycle hypothesis are also given. It is shown that the 13C record as we know it in planktonic and benthic foraminifera, the oxygen record as inferred from benthic foraminifera species distributions, and the early post glacial CaCo3 preservation event as recorded by aragonitic pteropods are consistent with both of the hypotheses presented. Only if an early post glacial spike in the 13C record for planktonic shells could be found would it be possible to eliminate one of these hypotheses (i.e., that involving shelf storage). The implications of these nutrient hypotheses to climate theory are as follows. If shelf storage is responsible for the glacial to interglacial CO2 increase, then the CO2 change must be considered an amplifier of some primary cause. The reason is that sea level changes are needed to drive deposition on (and erosion from) the shelves. On the other hand, if changes in the C P ratio for falling debris are responsible, then the CO2 change could either be an amplifier or a primary cause for the major glacial to interglacial climatic cycle. The latter is possible as self-sustained oscillations in ocean chemistry might be driven by interactions between ocean ecology and ocean nutrient chemistry.
An experiment in agent teaching by subject matter experts

This paper presents a successful knowledge-acquisition experiment in which subject matter experts who did not have any prior knowledge-engineering experience succeeded in teaching the Disciple- COA agent how to critique courses of action, a challenge problem addressed by the DARPA's High-Performance Knowledge Bases program. We first present the COA challenge problem and the architecture of Disciple- COA, a learning agent shell from the Disciple family. Then we present the knowledge acquisition experiment, detailing both the expert?Disciple interactions, and the automatic knowledge-base development processes that take place as a result of these interactions. The results of this experiment provide strong evidence that the Disciple approach is a viable solution to the knowledge acquisition bottleneck.
Asthma Management by Preschool Children and Their Families: A Developmental Framework

Sixty-one low-income, African-American mothers of preschool children with asthma were interviewed about asthma management. Additionally, 15 nurses provided information for a developmental schedule of asthma self-management activities. Most children had been diagnosed with asthma prior to age 18 months. Children participated in asthma management by 20 months, yet their mothers did not expect them to be able to manage their asthma by school age. Mothers expended considerable effort in coordinating asthma management with others. We suggest that asthma education with this population promote developmentally appropriate parent-child partnerships and effective involvement of family members and secondary settings.
The effect of β-carotene on lung and skin carcinogenesis

The induction of pre-cancerous squamous metaplasia in lungs of ferrets by high doses of dietary beta-carotene (BC) and cigarette smoke is compared with and contrasted to the different effects of high doses of dietary BC on skin papilloma and carcinoma induction by the two-stage carcinogenesis protocol. Whereas high dietary BC can inhibit the conversion of skin papillomas to carcinomas, such treatment would not be expected to inhibit smoke-induced lung tumors.
Crystal structure of Tritrichomonas foetus inosine-5'-monophosphate dehydrogenase and the enzyme-product complex.

Inosine-5'-monophosphate dehydrogenase (IMPDH) is an attractive drug target for the control of parasitic infections. The enzyme catalyzes the oxidation of inosine monophosphate (IMP) to xanthosine monophosphate (XMP), the committed step in de noVo guanosine monophosphate (GMP) biosynthesis. We have determined the crystal structures of IMPDH from the protozoan parasite Tritrichomonas foetus in the apo form at 2.3 A resolution and the enzyme-XMP complex at 2.6 A resolution. Each monomer of this tetrameric enzyme is comprised of two domains, the largest of which includes an eight-stranded parallel ‚/R-barrel that contains the enzyme active site at the C termini of the barrel ‚-strands. A second domain, comprised of residues 102-220, is disordered in the crystal. IMPDH is expected to be active as a tetramer, since the active site cavity is formed by strands from adjacent subunits. An intrasubunit disulfide bond, seen in the crystal structure, may stabilize the protein in a less active form, as high concentrations of reducing agent have been shown to increase enzyme activity. Disorder at the active site suggests that a high degree of flexibility may be inherent in the catalytic function of IMPDH. Unlike IMPDH from other species, the T. foetus enzyme has a single arginine that is largely responsible for coordinating the substrate phosphate in the active site. This structural uniqueness may facilitate structure- based identification and design of compounds that specifically inhibit the parasite enzyme.
Short tandem repeat polymorphism evolution in humans

Forty-five dinucleotide short tandem repeat polymorphisms were typed in ten large samples of a globally distributed set of populations. Although these markers had been selected for high heterozygosity in European populations, we found them to be sufficiently informative for linkage analysis in nonEuropeans. Heterozygosity, mean number of alleles, and mean number of private alleles followed a common trend: they were highest in the African samples, were somewhat lower in Europeans and East Asians, and were lowest in Amerindians. Genetic distances also reflected this pattern, and distances modelled after the stepwise mutation model yielded trees that were less in agreement with other genetic and archaeological evidence than distances based on differentiation by drift (FST). Genetic variation in nonAfricans seems to be a subset of that in Africans, supporting the replacement hypothesis for the origin of modern humans.
The effects of the HEALTHY study intervention on middle school student dietary intakes

Background: The HEALTHY study was designed to respond to the alarming trends in increasing rates of overweight, obesity, and type 2 diabetes mellitus in youth. The objective of this analysis was to examine the effects of the HEALTHY study on student self-reported dietary intakes (energy, macronutrients and grams consumed of selected food groups). Methods: HEALTHY was a cluster-randomized study in 42 public middle schools. Students, n = 3908, self-reported dietary intake using the Block Kids Questionnaire. General linear mixed models were used to analyze differences in dietary intake at the end of the study between intervention and control schools. Results: The reported average daily fruit consumption was 10% higher at the end of the study in the intervention schools than in the control schools (138 g or approximately 2 servings versus 122 g, respectively, p = 0.0016). The reported water intake was approximately 2 fluid ounces higher in the intervention schools than in the control (483 g versus 429 g respectively; p = 0.008). There were no significant differences between intervention and control for mean intakes of energy, macronutrients, fiber, grains, vegetables, legumes, sweets, sweetened beverages, and higher- or lower-fat milk consumption. Conclusion: The HEALTHY study, a five-semester middle school-based intervention program that integrated multiple components in nutrition, physical education, behavior change, and social marketing-based communications, resulted in significant changes to student’s reported fruit and water intake. Subsequent interventions need to go beyond the school environment to change diet behaviors that may affect weight status of children.
Differential effects of 3,4-methylenedioxypyrovalerone (MDPV) and 4-methylmethcathinone (mephedrone) in rats trained to discriminate MDMA or a d-amphetamine + MDMA mixture

Recent reports on the abuse of novel synthetic cathinone derivatives call attention to serious public health risks of these substances. In response to this concern, a growing body of preclinical research has characterized the psychopharmacology of these substances, particularly mephedrone (MEPH) or methylenedioxypyrovalerone (MDPV), noting their similarities to 3,4-methylenedioxymethamphetamine (MDMA) and cocaine. Few studies have utilized drug discrimination methodology to characterize the psychopharmacological properties of these substances. The present study employed a rodent drug discrimination assay to further characterize the stimulus effects of MEPH and MDPV in comparison to MDMA and to a drug mixture comprised of d-amphetamine and MDMA. Eight male Sprague-Dawley rats were trained to discriminate 1.5 mg/kg MDMA, and eight rats were trained to discriminate a mixture of 1.5 mg/kg MDMA and 0.5 mg/kg d-amphetamine (MDMA + AMPH) from vehicle. Substitution tests were conducted with MDMA, d-amphetamine, MDPV, MEPH, and cocaine. Dose-response curves generated with MDMA and MEPH were comparable between training groups. In contrast, AMPH, MDPV, and cocaine produced only partial substitution in animals trained to discriminate MDMA but produced full substitution in animals trained to discriminate the MDMA + AMPH mixture. These findings indicate that MDPV’s effects may be more similar to those of traditional psychostimulants, whereas MEPH exerts stimulus effects more similar to those of MDMA. Additional experiments with selective DA and 5-hydroxytryptamine (5-HT) receptor antagonists are required to further elucidate specific receptor mechanisms mediating the discriminative stimulus effects of MDPV and mephedrone.
Does transesophageal echocardiographic demonstration of a patent foramen ovale in patients with a recent cerebral ischemic event change anticoagulation therapy

Background Patent foramen ovale (PFO) is commonly demonstrated by transesophageal echocardiography (TEE) in patients with a recent transient ischemic attack or stroke. Our purpose was to determine how the TEE visualization of a PFO alters anticoagulation therapy. Methods We retrospectively identified 100 patients with transient ischemic attack or stroke referred for TEE; 50 had a PFO and 50 did not (control patients). Results Both groups were similar in regard to age, sex, the occurrence of transient ischemic attack versus stroke, and history of stroke. The PFO group had a higher incidence of a mobile interatrial septum, interatrial septal aneurysm, or both ( P P = .05) and aspirin use was discontinued in 9 of 50 patients with PFO versus 3 of 50 in the control group ( P = .12). Conclusion The main effect of demonstrating a PFO by TEE after an ischemic cerebral event was the institution of warfarin; there was a trend toward discontinuing aspirin.