cssi/SciSciGPT-SciSciNet huggingface dataset:
Species differences in Cl- affinity and in electrogenicity of SLC26A6-mediated oxalate/Cl- exchange correlate with the distinct human and mouse susceptibilities to nephrolithiasis

The mouse is refractory to lithogenic agents active in rats and humans, and so has been traditionally considered a poor experimental model for nephrolithiasis. However, recent studies have identified slc26a6 as an oxalate nephrolithiasis gene in the mouse. Here we extend our earlier demonstration of different anion selectivities of the orthologous mouse and human SLC26A6 polypeptides to investigate the correlation between species-specific differences in SLC26A6 oxalate/anion exchange properties as expressed in Xenopus oocytes and in reported nephrolithiasis susceptibility. We find that human SLC26A6 mediates minimal rates of Cl− exchange for Cl−, sulphate or formate, but rates of oxalate/Cl− exchange roughly equivalent to those of mouse slc2a6. Both transporters exhibit highly cooperative dependence of oxalate efflux rate on extracellular [Cl−], but whereas the K1/2 for extracellular [Cl−] is only 8 mm for mouse slc26a6, that for human SLC26A6 is 62 mm. This latter value approximates the reported mean luminal [Cl−] of postprandial human jejunal chyme, and reflects contributions from both transmembrane and C-terminal cytoplasmic domains of human SLC26A6. Human SLC26A6 variant V185M exhibits altered [Cl−] dependence and reduced rates of oxalate/Cl− exchange. Whereas mouse slc26a6 mediates bidirectional electrogenic oxalate/Cl− exchange, human SLC26A6-mediated oxalate transport appears to be electroneutral. We hypothesize that the low extracellular Cl− affinity and apparent electroneutrality of oxalate efflux characterizing human SLC26A6 may partially explain the high human susceptibility to nephrolithiasis relative to that of mouse. SLC26A6 sequence variant(s) are candidate risk modifiers for nephrolithiasis.
Are They Climbing the Pyramid? Rating Student-Generated Questions in a Game Design Project / Grimpent-ils la pyramide? Évaluation des questions produites par les étudiants dans un projet de conception de jeux

Researchers have examined the use of homemade PowerPoint games as an instructional technique to improve learning outcomes. However, test data have shown no significant difference in performance between high school chemistry students who created games and students who did not (Siko, Barbour, & Toker, 2011). One of the justifications for the use of the games is that students will, with practice, write higher-order questions when constructing the games. Two subject matter experts rated over 2,500 questions from games created by students in an environmental chemistry class through thematic analysis using Bloom’s taxonomy as a coding scheme. The students wrote primarily recall questions, and students who created games on two occasions did not write more questions than students who only created games once. This suggests that changes to the question-writing aspect of the game project may be necessary in order to see improvements in achievement when compared to control groups. Les chercheurs ont etudie l’usage de jeux PowerPoint maison en tant que technique pedagogique visant a ameliorer les resultats d'apprentissage. Les donnees des tests n'ont toutefois revele aucune difference significative quant au niveau de performance des etudiants du secondaire en chimie ayant cree des jeux et celui des etudiants n’en ayant pas concus (Siko, Barbour, et Toker, 2011). L’utilisation des jeux est notamment justifiee par l’idee que, pratique aidant, les etudiants ecrivent des questions plus complexes lorsqu’ils elaborent des jeux. Au moyen d’une analyse thematique utilisant la taxonomie de Bloom comme systeme de codification, deux experts chimistes ont evalue plus de 2500 questions provenant de jeux concus par des etudiants d’une classe de chimie environnementale. Les etudiants ont redige principalement des questions faisant appel a la memoire, et les etudiants ayant cree des jeux a deux reprises n’ont pas produit davantage de questions que ceux qui en etaient a leur premiere experience de creation de jeux. Il appert que des changements a la redaction des questions sont requis au projet de jeux pour pouvoir ameliorer la performance par rapport aux groupes temoins.
Chlamydial gene encoding a 70-kilodalton antigen in Escherichia coli: analysis of expression signals and identification of the gene product.

Abstract In an attempt to identify chlamydial genes whose native promoters allow them to be expressed in Escherichia coli, we isolated and characterized a chlamydial gene identified by screening a library of chlamydial DNA with antichlamydial antibodies. This gene encodes a 70-kilodalton immunoreactive polypeptide in E. coli hosts. Sequence analysis of the 5' portion of the gene identified its product as the chlamydial homolog of the E. coli ribosomal protein S1. The site of transcription initiation of the mRNA in chlamydiae was determined, and its putative promoter regions were identified. These regions apparently do not function efficiently in E. coli; in vitro transcripts generated by using E. coli RNA polymerase did not start at the authentic chlamydial initiation site. Several in vitro transcripts both larger and smaller than the authentic transcript were seen; presumably, these transcripts result from adventitious promoterlike elements in adjacent chlamydial DNA and may be responsible for the expression of the gene in E. coli.
DNA Probes as Tools for the Study of Host-Pathogen Evolution: the Example of Pseudomonas Solanaacearum

The use of DNA probes has made it possible to analyze the genomes of plant-pathogenic microorganisms isolated from virgin as well as cultivated areas, with the purpose of understanding how strains evolved in nature and how humans have perturbed the natural system. The bacterial plant pathogen, Pseudomonas solanacearum, represents a particularly useful system for these types of analyses because this bacterium has been found in pristine environments and the distribution of some strains on native plants and in virgin soils has been examined (Berg, 1971; Buddenhagen, 1960, 1985; Martin & French, 1977; Martin et al 1981; Sequeira & Averre, 1961). In addition, there is documented recent history of epidemics caused by: a) the introduction of new, susceptible hosts into virgin areas where the bacterium exists in association with native weeds and, b) the introduction of certain strains of the bacterium into geographic areas where these strains previously did not occur and where they developed the capacity to attack new host plants of great economic importance (Buddenhagen, 1985).
Crime and Uncertain Punishment in Transition Economies

Crime and Uncertain Punishment in Transition Economies We consider a continuum of agents in a transition country where the transfer of property rights has occurred. The transition is in progress and the nature of the governments future policies is unknown to the agents. Agents believe that the present government can evolve into one of two types: a traditional democratic government that supplies law enforcement and infrastructure leading to positive rm growth, or a corrupt government that may or may not provide law enforcement, does not provide a climate for rm growth, and may be con scatory. Each agent owns one rm, and we de ne an illegal action (crime) as the diversion of funds from this rm into the agents pocket. Each agent decides how much to steal, understanding that the amount he steals, and the government that will be in place, will a¤ect the taxes he pays. Agents further believe that the objective that each possible government wishes to achieve depends on, or is limited by, the taxes it collects. Since both the agentsdecisions and the tax revenue depend on the probability of each government type coming into existence, we endogenize the calculation of this probability. Using it, we determine the percentage of agents who steal, and investigate the relationship between the level of crime and uncertain political structure. JEL Classi cations: K42, P14, P26
Demonstration of efficient full-aperture type I/type II third harmonic conversion on Nova

Type I/Type II third harmonic conversion has been implemented at the 74 cm aperture of the Nova laser system. We discuss the performance capabilities and alignment issues of this scheme for Nova relative to conventional Type II/Type II conversion. 3 refs., 2 figs.
Properties of Diboron Tetrafluoride (B2F4), a New Gas for Boron Ion Implantation

Currently, boron trifluoride, BF3, is the primary feed gas for boron implantation in manufacturing of semiconductor devices. However, BF3 molecule is difficult to ionize and fragment, and therefore only a small fraction is is converted into B+ ions that can be used for ion implantation. This results in low B+ beam currents even at relatively high extraction currents, which can limit process throughput and system performance. The problem is particularly severe at low energies. ATMI has demonstrated that use of diboron tetrafluoride, B2F4, as a feed gas for boron implantation may offer advantages over BF3. It has been shown that B2F4 is capable of generating higher B+ and BF2+ beam currents at lower ion source power settings, and that the molecule can be used on the existing installed base of implanters without any major equipment modifications.
“Breaking Bad” in Black and White: What Ideological Deviance Can Tell Us about the Construction of “Authentic” Racial Identities

This article contributes to the study of racial-group politics by examining how Black and White Americans create authentic racial identities through the regulation of ideological adherence to color-consciousness and color-blindness, respectively. The article first theorizes about the relationship between racial ideology and racial authenticity. We then illustrate our hypotheses through an analysis of responses of Black and White racial group members to Black conservatives and White racial justice activists, whose viewpoints and agendas are read as contradictory to the broad goals of the majority of their racial counterparts. We explore, through an examination of empirical instances of chastisement, exclusion, and public de-authentication of individuals who deviate from the dominant ideology of their racial group, some of the ways Black and White Americans attempt to control in-group political behavior and to enforce indigenous standards for group-based public representation.
Visualizing changes in mitochondrial Mg2+ during apoptosis with organelle-targeted triazole-based ratiometric fluorescent sensors

Magnesium is one of the most abundant metals in cells and is essential for a wide range of cellular processes. Magnesium imbalance has been linked to a variety of diseases, but the scarcity of sensors suitable for detection of Mg2+ with subcellular resolution has hampered the study of compartmentalization and mobilization of this ion in the context of physiological and pathological processes. We report herein a family of fluorescent probes for targeted detection of free Mg2+ in specific intracellular organelles, and its application in the study of programmed cell death. The new sensors feature a triazole unit that plays both structural and electronic roles by serving as an attachment group for targeting moieties, and modulating a possible internal charge transfer process for ratiometric ion sensing. A probe decorated with an alkylphosphonium group was employed for the detection of mitochondrial Mg2+ in live HeLa cells, providing the first direct observation of an increase in free Mg2+ levels in this organelle in the early stages of Staurosporine-induced apoptosis.
Development and evolution of the pharyngeal apparatus

The oral or pharyngeal apparatus facilitates the dual functions of respiration and feeding. It develops during embryogenesis from transient structures called pharyngeal arches, which comprise a reiterated series of outgrowths on the lateral side of the head. The pharyngeal arches and their segmental arrangement are highly conserved throughout evolution from invertebrate chordates such as amphioxus, through to vertebrate agnathans including avians, squamates and mammals. The structural organization of the pharyngeal arches is also highly conserved and involves contributions from each of the three primary endoderm, mesoderm and ectoderm germ layers. The endoderm is particularly important for pharyngeal arch formation and segmentation and also plays a critical role in tissue specific differentiation. The ectoderm gives rise to neural crest cells (NCC) which provides an additional layer of complexity to pharyngeal arch development and differentiation in vertebrates compared to invertebrate chordates that do not possess NCC. Collectively the pharyngeal arches give rise to much of the neurovasculature and musculoskeletal systems in the head and neck. The complexity of development renders the pharyngeal apparatus prone to perturbation and subsequently the pathogenesis of birth defects. Hence it is important to understand the signals and mechanisms that govern the development and evolution of the pharyngeal complex.
GeoLens: Enabling Interactive Visual Analytics over Large-Scale, Multidimensional Geospatial Datasets

With the rapid increase of scientific data volumes, interactive tools that enable effective visual representation for scientists are needed. This is critical when scientists are manipulating voluminous datasets and especially when they need to explore datasets interactively to develop their hypotheses. In this paper, we present an interactive visual analytics framework, GeoLens. GeoLens provides fast and expressive interactions with voluminous geo-spatial datasets. We provide an expressive visual query evaluation scheme to support advanced interactive visual analytics technique, such as brushing and linking. To achieve this, we designed and developed the Geohash based image tile generation algorithm that automatically adjusts the range of data to access based on the minimum acceptable size of the image tile. In addition, we have also designed an autonomous histogram generation algorithm that generates histograms of user-defined data subsets that do not have pre-computed data properties. Using our approach, applications can generate histograms of datasets containing millions of data points with sub-second latency. The work builds on our visual query coordinating scheme that evaluates geo-spatial query and orchestrates data aggregation in a distributed storage environment while preserving data locality and minimizing data movements. This paper includes empirical benchmarks of our framework encompassing a billion-file dataset published by the National Climactic Data Center.
The regulation of ornithine aminotransferase synthesis by glucagon in the rat.

Abstract Ornithine aminotransferase (OAT) from rat liver mitochondria was purified to homogeneity. A monospecific antiserum against the enzyme protein was prepared in rabbits. Immunotitrations were performed on OAT present in crude mitochondrial extracts obtained from the livers and kidneys of rats in several hormonal and dietary states. No evidence was found for the existence of an immunologically reactive but enzymatically inactive form of OAT. The relative rate of enzyme synthesis in vivo was studied by pulselabeling rats with [4, 5-3H]leucine, isolating the enzyme protein by immunoprecipitation, and dissociating the immunoprecipitates on sodium dodecyl sulfate-acrylamide gels. Nine hours after a single subcutaneous injection of a glucagon oil emulsion, a 3-fold increase in OAT activity and a 12-fold increase in the synthetic rate of the enzyme were observed. Serine dehydratase activity increased on a time-course very similar to that of OAT following glucagon injection. These increases occurred only on low (0–12.5%) protein diets. At higher levels of dietary protein (30% and up), no further stimulation of OAT synthesis by glucagon was observed. Administration of actinomycin D within the first 2 h after glucagon injection resulted in an inhibition of OAT induction. When the administration of the antibiotic was delayed until 4 h after glucagon, no inhibition of OAT induction was observed. Glucose repression of the glucagon induction of the enzyme in hepatic mitochondria was demonstrated to be the result of a rapid inhibition of OAT synthesis.
Cardiac extracellular potentials. Analysis of complex wave forms about the Purkinje networks in dogs.

Extracellular recordings of normal action potentials, action potentials at reduced temperature, and action potentials initiated when the membrane was partially depolarized due to elevated extracellular potassium were made at varying distances from the surface of Purkinje strands of the dog left ventricle. As the electrode was withdrawn from the surface, the time between the positive and negative peaks increased; the amplitude of the simple biphasic wave form decreased markedly at first, and, thereafter, it decreased more gradually. The extracellular wave forms could be described by a single equation for all distances right up to the membrane surface even in the presence of interventions which drastically changed the intracellular potential and the conduction velocity. Wave forms of extracellular potentials at varying distances from the strand were computed from intracellular potentials and showed good agreement with the measured wave forms. Most major bundles in the dog conduction system have polyphasic extracellular wave forms rather than the relatively simple kind characteristic of the single strand. By using the equation that describes how the extracellular potential about a single strand varies as a function of distance, it was shown that the recorded polyphasic wave forms of the bundle studied resulted from the superposition of potentials from a number of asynchronously excited strands situated at varying distances from the recording electrode instead of from an underlying complex intracellular action potential. Extracellular recordings were chosen over intracellular recordings for this study, because they can indicate the presence of more than one excitation wave in a single record, thus permitting the resolution of the sequence of activation of the conduction system to its most elementary level.
Simulating Social Network Formation: A Case-Based Decision Theoretic Model

Social networks depict complex systems as graph theoretic models. The study of the formation of such systems (or networks) and the subsequent analysis of the network structures are of great interest. For information systems research and its impact on business practice, the ability to model and simulate a system of individuals interacting to achieve a certain socio-economic goal holds much promise for proper design and use of cyber networks. We use case-based decision theory to formulate a customizable model of information gathering in a social network. In this model, the agents in the network have limited awareness of the social network in which they operate and of the fixed, underlying payoff structure. Agents collect payoff information from neighbors within the prevailing social network, and they base their networking decisions on this information. Along with the introduction of the decision theoretic model, we developed software to simulate the formation of such networks in a customizable context to examine how the network structure can be influenced by the parameters that define social relationships. We present computational experiments that illustrate the growth and stability of the simulated social networks ensuing from the proposed model. The model and simulation illustrates how network structure influences agent behavior in a social network and how network structures, agent behavior, and agent decisions influence each other.
Homocysteine in Sickle Cell Disease : Relationship to Stroke

Abstract PURPOSE: The risk factors and pathophysiology of stroke and other serious complications of sickle cell disease (SCD) are poorly defined. Hyperhomocysteinemia has recently been identified as a risk factor for stroke and other vascular diseases in the general population, however its role in SCD has not been investigated. PATIENTS AND METHODS: We measured serum homocysteine and red cell folate levels in 100 patients with SCD, including 16 patients with stroke. A disease severity score was determined for all patients and those without stroke were classified into mild (44 patients) or severe (40 patients) disease groups. RESULTS: Homocysteine levels for the stroke group (median 13.3 μmol/L, mean 13.1 ± 4.3 μmol/L) were significantly higher than those in patients without stroke (median 9.7 μmol/L, mean 10.7 μmol/L) ( P P P CONCLUSION: High homocysteine levels may be a risk factor for development of stroke in SCD patients. The role of homocysteine in the pathogenesis of stroke in SCD needs to be examined in a longitudinal, prospective study.
Biogenesis of galactocarolose by Penicillium charlesii. I. Incorporation of C14 from glucose-C14 and dl-tartrate-1,4-C14 into polygalactose

Abstract Penicillium charlesii A.T.C.C. strain 1887 grown upon various glucose-C 14 compounds and dl -tartrate was shown to incorporate C 14 into an acid-labile polygalactose elaborated into the medium. The specific activity of the galactose isolated was about one-half the initial specific activity of glucose-2-C 14 and about one-third the initial specific activity of d -glucose-U-C 14 . The results are discussed in terms of catabolism of glucose to two identical 2-carbon compounds followed by the combination with a 4-carbon unit derived from tartrate, to form a galactose derivative.
The behavior of a fast-responding barbituric acid potential-sensitive molecular probe in bovine heart submitochondrial particles

The barbituric acid probe diBa-C2-(5) responds to the formation of a membrane potential (ΔΨ) in bovine heart submitochondrial particles (SMP) by a CCCP-reversible, 5–7 nm red shift of the probe absorption spectrum. This shift can be enhanced by the addition of nigericin, an observation that indicates that the probe is specifically sensitive to ΔΨ. Probe-SMP binding analyses indicate that, relative to the resting state, the ratio of the dye dissociation constant to the maximum number of binding sites decreases by a factor of 30 when ΔΨ is generated. This observation suggests that the origin of the potential-dependent shift of the probe absorption spectrum is increased occupancy of the SMP membrane by diBa-C2-(5). The time course of the ATP-induced diBa-C2-(5) spectral shift in SMP was complete in nominally 0.2 s and could be described by a single-exponential rate equation. There was no evidence for a slower-phase signal when the data collection time period was increased to 250 s. The apparent first-order rate constants obtained from the single exponential analyses of the barbituric acid ATP-generated signal, however, were a linear function of probe concentration at fixed SMP membrane concentration. The resulting second-order rate constant obtained by linear regression was nominally 1 · 107 M(dye)−1 s−1; this value is two to three orders of magnitude higher than that of a number of other well-established probes of ΔΨ in mitochondrial preparations. Based on the invariance of the kinetics of the oxidation of cytochromes c and c1 by ATP-driven reversed electron transport in the presence and absence of the probe, diBa-C2-(5) does not appear to permeate the SMP membrane on a time scale of milliseconds to several minutes.
How Important is Improved Water Infrastructure to Microenterprises? Evidence from Uganda

Abstract Despite the proliferation of micro and small enterprises (MSEs) in sub-Saharan Africa (SSA), most have difficulty surviving, let alone expanding their operations. Using empirical evidence from two Ugandan towns we explore the impact of investments in water supply infrastructure on MSEs. Our findings suggest that, despite perceptions among firm owners that water supply is a binding constraint, economic benefits to MSEs of supply improvements may be limited. Current water infrastructure planning strategies may be based on erroneous assumptions about the relative demand for improved water supply by firms and households, as well as the feasibility of cross-subsidies between groups of users.
Polychlorinated Biphenyls and Non-Hodgkin Lymphoma

Several epidemiologic studies suggest that polychlorinated biphenyl (PCB) levels measured in peripheral blood or adipose tissue are related to increased risk of non-Hodgkin lymphoma (NHL) and, therefore, may be at least partially responsible for the rising incidence of NHL unrelated to HIV infection in recent decades. Case-control studies that measured PCBs in blood, adipose tissue, or household carpet dust, at the time of diagnosis, have observed elevated NHL risk associated with concentrations of either total PCBs or of specific congeners. Similar associations have been found in a number of prospective cohorts. These associations do not seem to be due to confounding by other organochlorines or by other known NHL risk factors. These results support evidence of PCB carcinogenicity from animal studies. However, interpretation of the epidemiologic evidence is limited by the wide range in measurement precision across congeners and by the moderate to high correlation among many congeners. Occupational cohort studies provide very limited support for a relationship between PCBs and NHL. In conclusion, there is mounting evidence of a relationship between certain PCBs and risk of NHL, but important questions remain, especially regarding the magnitude, timing, and causality of that relationship.
In vivo chain elongation of hepatic DNA: 1-β-D-arabinofuranosyl cytosine sensitive and insensitive steps

Abstract The in vivo chain elongation of rat liver DNA following partial hepatectomy was studied using alkaline sucrose gradients. DNA made in 5 min was less than 4 × 10 7 daltons and that made in 30 min was heterodisperse and by 4 hr 75% of the DNA became larger than 1 × 10 9 daltons. Administration of 1-β-D-arabinofuranosyl cytosine (ara-C) 5 min after thymidine- 3 H injection inhibited the chain elongation, whereas if given 30 minutes after thymidine- 3 H pulse did not inhibit the chain elongation. Thus the in vivo chain elongation of rat liver DNA consists of at least two steps 1) a step sensitive to ara-C involving nucleotides addition and 2) the other insensitive to ara-C and probably involving ligation of polynucleotide chains.
Charm and botom baryon masses in the 1/N expansion

Abstract The masses of heavy quark baryons are studied in an expansion in 1/Nc, SU(3) flavor symmetry breaking, and heavy-quark symmetry breaking. Very accurate model-independent mass relations are obtained for charm and bottom baryons.
Flat-flame combustion synthesis of diamond

The synthesis of well-crystallized diamond has been achieved by a wide variety of CVD techniques including plasma assisted methods (DC, RF and microwave), hot wire methods and by oxyacetylene combustion. These can be differentiated from other carbon coatings (graphite, vitreous carbons, and DLC) by Raman spectroscopy, X-ray diffraction and scanning electron microscopy. The high linear growth rates reported for the small area flame deposition of diamond and the recent demonstration of optically transparent continuous diamond films using 'torch' growth methods has led to speculation that by enlarging the area of uniform combustion it might be possible to deposit tens of square centimeters of transparent diamond at reasonable rates using relatively inexpensive equipment. We have previously reported that samples prepared by oxyacetylene combustion at low pressure were highly non-uniform and that higher oxygen/acetylene ratios were required than those found successful at atmospheric pressure using common brazing or welding torches. This paper reports low pressure flat flame combustion growth at still higher 02/C2H2 gas ratios and a new Raman feature at —1280 cm1 which was observed in some experiments in addition to the expected diamond peak at 1332 cm. Using data from previously published work on a similar flame composition, we speculate that the locations in the flame yielding diamond (as opposed to non-diamond forms of solid carbon) correspond to regions of the highest atomic hydrogen mole fraction (partial pressure) which in turn is closely related to the highest partial pressure of numerous reactive hydrocarbon radicals including the methyl radical. The increased oxygen/acetylene ratio needed for diamond deposition in these experiments may well be related to the much lower than adiabatic flame temperature expected and observed in previous work on oxyacetylene combustion at low pressure using a water cooled flat flame burner.
Combination High Dose Amrinone and Dopamine in the Management of Moribund Cardiogenic Shock After Open Heart Surgery

Two patients who suffered severe cardiogenic shock after open-heart surgery were successfully resuscitated with high doses of amrinone and dopamine. Both patients had required cardiopulmonary resuscitation and neither was responsive to more conventional mechanical and pharmacologic intervention. Neither patient suffered any serious side effects and both were eventually discharged from the hospital in good condition. These two case reports suggest the potential for using higher than previously reported doses of amrinone in combination with dopamine for the successful treatment of moribund cardiogenic shock in the post open-heart surgical patient. Further studies are needed to assess whether this high-dose drug combination will be successful in patients who present with severe cardiogenic shock unrelated to the post open-heart surgical setting. (Chest 1988; 94:503-06)
Studies of the binding of sulfur released in the mixed-function oxidase-catalyzed metabolism of diethyl p-nitrophenyl phosphorothionate(parathion) to diethyl p-nitrophenyl phosphate (paraoxon).

Abstract Incubation of [35S]labeled parathion with rat liver microsomes in the presence of an NADPH-generating system leads to the covalent binding of sulfur to the macromolecules of the microsomal membrane. The maximal binding of sulfur to microsomes requires the presence of NADPH, is increased using microsomes from phenobarbital and 3-methyl-cholanthrene-treated animals, and is inhibited by carbon monoxide. The majority, if not all, of the sulfur bound is in a form free of the remainder of the parathion molecule. These findings, coupled with the fact that the apparent Km and Vmax for sulfur binding are not statistically different from the apparent Km and Vmax for metabolism of parathion to paraoxon, indicate the sulfur bound is that released in the mixed-function oxidase-catalyzed metabolism of parathion to paraoxon. Under the conditions of the experiments described in this report, the binding of sulfur to microsomes decreases the concentration of cytochrome P-450 in the microsomes and inhibits slightly the rate of the mixed-function oxidase-catalyzed metabolism of benzphetamine.
The behavioral treatment of child and adolescent posttraumatic stress disorder

Abstract The inclusion of posttraumatic stress disorder (PTSD) in the American Psychiatric Association's (APA) Diagnostic and Statistical Manual of Mental Disorders (DSM-III, 1980) has been associated with an exponential increase in the number of stress-related publications ( Saigh, 1992a ). Despite the increased literature base, it is of interest to note that the majority of these studies have involved traumatized adults (e.g., combat veterans or rape victims). Nevertheless, it is also of interest to note that child-clinical investigators have made conceptual and practical advances that are of considerable relevance to the study of child and adolescent PTSD. This review will primarily focus on interventions that have evinced efficacy over time with a wide range of traumatized patients. In so doing, historical, theoretical, and practical information relative to the use of flooding regiments is provided.
Investigations into the potential for embryo transfer from infected cows without transmission of infection

Thirty-six attempts were made to isolate Brucellaabortus from the uterine flushings of culture positive and serologic reactor cows. Sixteen of these attempts were made after cows had been programmed for superovulation and a simultaneous attempt was made to recover eggs. Udder secretion samples for culture and blood for serology were collected at the time of the flushing procedure. In addition, a field isolate of Brucellaabortus suspended in three different solutions (one commonly used for nonsurgical embryo retrieval) was quantitated at various intervals up to 24 hours. Brucellae were not cultured from any of the uterine flushings although it was demonstrated that the organisms would remain viable in the media used for up to 24 hours. Udder secretions contained brucella at the time of flushing in 17 of the 36 attempts. Results indicated that transfer from infected donors might be achieved without transfer of infection. It is cautioned that final evidence of success would have to come after recipients had undergone serologic and cultural surveillance through their gestation period.
Enzyme cofactors: Double-edged sword for catalysis

The metal cofactors responsible for the activity of CDK2 — a representative member of the kinase superfamily of enzymes — have now been shown to also have inhibitory effects during the catalytic cycle.
151 Engineering a Human ‘Skin” with Adult Primary Cells.

The inability to experiment in humans creates a great need to develop culture systems that mimic human tissues/organs. Skin is arguably the simplest human tissue and therefore provides an excellent prototype for tissue engineering. Moreover, skin is the body’s first line of defense. Currently available skin replacements have been classified into four categories: (i) those that are composed completely of epidermal cells; (ii) those consisting of dermal components derived from processing of cadaver skin or from collagen and other matrix molecules; (iii) those containing both dermal and epidermal components and (iv) those that contain dermal, epidermal and vascular components. All of these substitutes have drawbacks. Therefore, there is a need for skin replacements that: (a) are prepared with pertinent primary human cells but yet can be ready “off” the shelf; (b) can be prepared rapidly; (c) contain stable structures in particular microvessels that can rapidly connect with the patient’s vasculature in this manner establish circulation in the “graft” increasing the chances of survival; (d) can be tailored for specific wound impairments (e) are long lasting. We have developed a new generation human “skin” that can fulfil these requirements and can potentially be used as a “living bandage”. We start with three primary human cell types and a collagen matrix that self-assemble into a connective tissue containing a network of mature microvessels, is covered with a stratified epidermis, expresses biochemical markers, matrix molecules, and cytokines characteristic of normal human skin and matures in 10–15 days. Moreover, two additional cell types, pericytes and monocytes, differentiate in situ adjacent to and within microvessels, respectively providing stability to the micriovessels and the epidermis expresses keratins that are typical of mature skin and not those characteristically produced in response to injury such as keratins 6, 16, 17. This tissue can potentially be developed into a skin replacement for patients with impaired healing. In addition, this tissue responds normally to bological stimuli, providing a powerful vehicle to investigate mechanisms of skin development and regeneration, understand pathological processes, and test drugs and treatments for skin diseases
Sex Rules: The Edicts of Income in Exotic Dancing

This research examines how dancers view the rules that are intended to control/regulate the interaction between customer and dancer. Rules from a variety of clubs are examined. Data were gleaned from interviews with 133 female dancers in several cities and level of clubs. Data from dancers indicate these rules, in practice, allow dancers to control their sexuality and activities and thereby benefit in the form of income.
The Role of Race and Gender in T Cell Responses in Children Perinatally Infected with HIV-1

Understanding the immunologic mechanisms that can control the progression of HIV disease is paramount for the development of vaccines or of new strategies for immunotherapy. Whether infection occurs perinatally, sexually, or parenterally, disease ultimately develops in all but a very few individuals, although the time to disease is quite variable. This tremendous variability in disease progression may be influenced by age at the time of infection, viral load, race, and host genetic factors, most notably HLA class and CCR5 [1–8]; however, the influence of gender is more controversial. Additionally, there is evidence that these same factors may also protect against infection in some individuals and in certain settings.
Age-related differences in body weight loss in response to altered thyroidal status.

To determine whether age-related differences in body weight loss in hyperthyroidism could be related to caloric intake, the body weight and food consumption of Fischer 344 male rats were monitored every other day for four weeks. Six-month-old (young) rats were compared to 16-month-old rats (intermediate age) and 25-month-old (aged) rats. Hypothyroidism was induced with 0.025% methimazole in the drinking water for four weeks. Hyperthyroidism was induced with triiodothyronine (T3) injections (15 micrograms/100 g body weight i.p.) for the last 10 days of observation. A group of young rats pair fed with aged rats was included as a control group. The body weight changes of aged rats were similar to hypothyroid young rats. An index of T3 catabolic effect was calculated based on the net weight loss and food intake. This index was not different in aged rats compared to young rats. The apparent hypersensitivity of aged rats to T3 as evidenced by excessive weight loss could totally be attributed to decreased caloric intake. It is concluded that aged rats compared to the young are not more sensitive to the overall catabolic effects of thyroid hormones.
IPEB transcription factor regulating the intracisternal a particle gene during F9 cell differentiation is expressed at sites of lymphoid development

The murine intracisternal A particle (IAP) proviral elements are expressed at low levels in undifferentiated F9 embryonal carcinoma cells but are highly expressed when F9 cells are induced to differentiate into parietal endoderm-like cells. IAP elements are also expressed in parietal endoderm-like PYS-2 cells. We previously identified an IAP proximal enhancer (IPE) element that mediates a F9 differentiation-specific enhancer activity. We also identified a 60 kDa IPE binding (IPEB) protein whose activity is high in PYS-2 cells, where IAP is expressed, but very low in F9 cells. Transcription of IAP elements has also been shown in the adult mouse thymus and in activated splenic B cells. We have now shown by DNA affinity chromatography, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and band-shift analysis that the 60 kDa IPEB is expressed in adult T lymphocytes and in resting as well as lipopolysaccharide activated splenic B cells but not in adult liver cells, suggesting an important role for IPEB in IAP transcription in vivo. In addition, we find IPEB expressed in the fetal mouse at sites of lymphoid development, such as the liver, spleen, and thymus, suggesting it may play an important role in gene expression during lymphoid development. In support of this, we find IPEB in the human T cell tumor lines, Jurkat and Molt 13, as well as the Daudi B cell line and in the normal calf thymus and in the thymus and spleen of the chicken and rat.
Disparate Effects of Triphenylethylene Antiestrogens on Estrogen and Progestin Biosyntheses by Cultured Rat Granulosa Cells

The influence of triphenylethylene antiestrogens on FSH-stimulated production of estrogen, progesterone, and 20α-hydroxy-4-pregnen-3-one (20α-OH-P) was examined in cultured rat granulosa cells. The cells were cultured with increasing concentrations of FSH, with or without diethylstilbestrol (DES) or various antiestrogens. After 3 days, medium progesterone and 20α-OH-P contents were determined. Cells were reincubated for an additional 8 h with Δ4-androstene-3,17-dione, and estrogen formation was measured. Steroid production was negligible by cultures treated with DES or antiestrogens alone. FSH treatment increased estrogen and progestin production, while the addition of DES (10−7 m) further enhanced FSHstimulated steroidogenesis. Likewise, treatment with 10−6 m of the antiestrogens tamoxifen (Tarn), nafoxidine (Naf), or clomiphene citrate (CC) also enhanced FSH-stimulated aromatase activity. In contrast, the antiestrogens each inhibited FSH stimulation of progesterone and 20α-OH-P production (>73% inhibiti...
Factor X bound to the surface of activated human platelets is preferentially activated by platelet-bound factor IXa.

Factor X is a zymogen in the blood coagulation system which is activated by the serine protease, factor IXa, in a reaction that is promoted by the presence of stimulated platelets. We have shown previously that platelets possess a binding site for factor IXa, the occupancy of which is correlated with the rate of factor X activation (Ahmad et al., 1989b,c). Similarly, we have described a different binding site on the surface of activated platelets to which the substrate for this reaction, factor X, can bind (see the accompanying paper). This “zymogen binding site” is of moderate affinity and is relatively nonspecific; apparently shared to some degree by factor X and other vitamin K-dependent proteins, most notably prothrombin. We have found that prothrombin fragment 1 not only is able to displace factor X from this platelet binding site but also possesses the ability to inhibit the platelet-dependent activation of factor X. We have developed two mathematical models for the activation of factor X by platele...
Model system for testing the efficacy of antioxidants in muscle foods.

The objective of this research was to study the effect of the antioxidants, δ-tocopherol, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), tertiary butylhydroquinone (TBHQ), and propyl gallate in a model system of lean muscle and canola oil and to compare the effects with those in minced herring. Two carrier solvents with different dielectric constants (e), ethanol (e = 24) and oil (e = 2), were used. Oxidation was measured using thiobarbituric acid reactive substances (TBARS) and sensory analysis. In both the lean muscle−canola oil model system and in herring muscle, the hydrophilic antioxidants, propyl gallate and TBHQ, were more effective in providing oxidative stability than the lipophilic antioxidants, δ-tocopherol and BHT. The oxidative stability of a cod muscle−canola oil system in the presence of propyl gallate, and δ-tocopherol was not affected by the dielectric constant of the carrier solvent, while BHA was more effective as an antioxidant when added in the polar solvent ethanol. ...
Assessing urgency in interstitial cystitis/painful bladder syndrome

Objectives Interstitial cystitis/painful bladder syndrome (IC/PBS) at present is a symptom-based diagnosis. The Interstitial Cystitis Symptom Index (ICSI), also known as the O'Leary-Sant Symptom Index, is a widely used scale that assesses the four cardinal symptoms of IC/PBS (ie, bladder pain, urgency, frequency, and nocturia), by asking how often each is experienced. In an ongoing case-control study of recent-onset IC/PBS, we compared the ICSI with a series of questions that addressed the severity of these symptoms. Methods Recruiting nationally, we enrolled women with IC/PBS symptoms of 12 months' duration or less. We assessed the severity of pain, frequency, and urgency using Likert and categorical scales, and how often these symptoms were experienced using the ICSI. We compared these scales by frequency distributions and interscale correlations. Results In 138 women with recent-onset IC/PBS, the scores for frequency were correlated and, for pain, appeared to be complementary. However, for urgency, the ICSI question of "the strong need to urinate with little or no warning" consistently yielded lower scores than the severity question of "the compelling urge to urinate that is difficult to postpone." Some patients denied urgency to the ICSI question yet reported intense urgency to the severity question. Conclusions Compared with the severity question, the ICSI underestimated the prevalence and degree of urgency. This observation is consistent with the views of others that sudden urgency does not define the sensation experienced by many patients with IC/PBS. Clarifying this symptom description may assist in developing a usable case definition for IC/PBS.
Characterization of 2- and 3-Methoxy in Ubiquinone Binding and Redox Tuning within the Photosynthetic Reaction Center of Rhodobacter Sphaeroides

Ubiquinone is a universal, membrane-associated redox mediator. The redox properties of ubiquinone in vivo are closely controlled both by its electrostatic environment within the binding sites of proteins and by steric interactions determining its conformation. Recent experimental work suggests that differences in the angle of the two methoxy side chains with respect to the quinone ring plane dictate the redox potential difference between the two quinone binding sites, however the specific quinone-protein interactions that alter the redox potential could not be identified.In order to ascertain which specific interactions between the quinones and their environment tune the redox potential, molecular dynamics simulations of ubiquinone bound to the QA and QB sites of the photosynthetic reaction center (RC) of Rhodobacter Sphaeroides were compared with complementary studies done on ubiquinone analogs lacking either the 2- or 3-methoxy group. Since prior ubiquinone parameters were biased towards non-native methoxy angles, systematically parameterized ubiquinone and its analogues to accurately describe the structure and dynamics of the methoxy groups.The removal any methoxy group showed little impact on the QA binding. However, both the binding conformation and the methoxy dihedral angle distribution in the QB site were significantly altered upon removal of the 2-methoxy group. We observe that the 2-methoxy group in the QB site is oriented approximately normal to the ring plane. This orientation is favored by a weak hydrogen bond between the 2-methoxy oxygen and the amine of GLY225. A more out of plane methoxy (as imposed by the protein environment) would correspond to a higher electron affinity of QB over QA. We propose this hydrogen bond as the mechanism whereby the redox potential is tuned to promote inter-quinone electron transfer in the RC.
Aggressive Management of HELLP Syndrome and Eclampsia

The nursing care of women critically ill during pregnancy is an ever-changing specialty that presents unique clinical problems and issues. The woman and the fetus can be profoundly affected by the hypertensive disorders of pregnancy. The underlying pathology must be identified in relation to its effects on the pregnancy, the effects of the pregnancy on the disease, and the implications for the woman and the fetus. Severe preeclampsia, the HELLP syndrome (hemolysis, elevated liver enzymes, and low platelets), and eclampsia present such challenges and management problems. This article discusses the pathophysiology and management implications of severe preeclampsia, the HELLP syndrome, and eclampsia.