Hemoglobin switching in sheep and goats. VI. Commitment of erythroid colony-forming cells to the synthesis of betaC globin

Bone marrow from mature goats and sheep was cultured in plasma clots, and three erythropoietin (ESF)-dependent responses-growth (colony formation), differentiation (globin production), and initiation of hemoglobin C (alpha2beta2C) synthesis--were quantitated. ESF concentrations below 0.01 U/ml supported colony growth and adult hemoglobin production in cultures of goat marrow, while maximal hemoglobin C synthesis (70%), as measured between 72 and 96 h in culture, required a 100-fold higher ESF concentration. Sheep marrow was cultured in a medium enriched to enhance growth and to permit complete maturation of colonies. These colonies active in hemoglobin synthesis between 24 and 96 h produced mainly adult hemoglobin, and only between 96 and 120 h did sheep colonies develop which produced mainly hemoglobin C (up to 70%). A similar heterogeneity may exist among goat colonies. Thus, when goat bone marrow was fractionated by unit gravity sedimentation, more hemoglobin C synthesis was observed in colonies derived from cells of intermediate sedimentation velocity than in colonies derived from the most rapidly sedimenting cells. Brief exposure of sheep (in vivo) and goat (in vitro) bone marrow to a high ESF concentration committed precursor cells to the generation of colonies which, even at low ESF concentration, produced hemoglobin C. Committment to hemoglobin phenotype appears to be an early and probably irreversible event in the development of an erythroid cell.     

Hemodynamic and ventilatory effects associated with increasing inverse inspiratory-expiratory ventilation

Rational modification of an existing cationic alpha-helical antimicrobial peptide (ESF1) for improved activity by increasing amphipathicity was undertaken. ESF1 and two variants (GR7 and SA3) were synthesized and tested for activity range, minimum inhibitory concentration, and hemolytic activity. Biological activity was related to structure as determined by circular dichroism. The substitution of arginine for glycine in position seven was found to increase antimicrobial activity without effecting hemolysis. Increased activity was related to stronger alpha-helix formation in buffer. Increased beta-sheet formation in micellar SDS was observed and speculated to be due to a stronger ability of the variants to form multimolecule complexes, a feature consistent with existing models of cationic peptide activity.     

双极串联技术在5t电渣炉的设计与应用

叙述了双极串联技术及恒功率、恒熔速控制在电渣炉的设计与应用，以及获得的经济效益。该结构型式是降低电渣炉冶炼电耗的有效措施，在国内外推广使用。     

Electronic animal identification for controlling feed delivery and detecting estrus in gilts and sows in outside pens

The objective of the present study was to evaluate the feasibility of delivering feed and detecting estrous behavior by computer-controlled equipment in a nonconfinement environment. In Exp. 1, gilts were assigned to treatment when detected pregnant by ultrasound at 30 to 35 d after artificial insemination. They were assigned to be fed individually in stalls once/day (0830) with a scoop (controls, n = 20) or with an electronic sow feeding station (ESF, n = 20). The ESF gilts received their feed in 98.6-g aliquots at 80-s intervals as they visited the feeding station. Control vs ESF gilts did not differ (P > .8) for backfat (2.2 vs 2.1 cm) or weight (170 vs 172 kg) before farrowing, total and live pigs/litter (9.3 and 8.7 vs 9.1 and 8.8), or litter birth weight (12.7 vs 12.1). In Exp. 2, proceptive behavior, as measured by visits to a boar's pen, were recorded electronically, and observed estrus was evaluated in two groups of sows during their first (n = 11) and second and third (n = 19) estrous cycles and in one group of gilts (n = 14). A partition prevented visual and physical contact between the boar and the visiting females except where the electronic estrus detection (EED) station was installed. Feed delivery software was used to monitor boar visitation even though no feed delivery equipment was present at the boar pen.(ABSTRACT TRUNCATED AT 250 WORDS)     

Pedicled external spermatic fascia flap for urethroplasty in hypospadias and closure of urethrocutaneous fistula

PURPOSE: To prevent the development of urethrocutaneous fistula after urethroplasty for hypospadias or recurrence after closure of a urethrocutaneous fistula, the authors developed a new simple technique wherein the readily available external spermatic fascia (ESF) surrounding the testis and cord is used as a pedicled blanket flap to cover the neourethra or the site of closure of a urethrocutaneous fistula. RESULTS: In three patients who had urethroplasty for hypospadias incorporating our ESF flap procedure, no urethrocutaneous fistula developed. It was also effective for closure of urethrocutaneous fistula in five patients, some of whom had had recurrent fistula formation.     

30t～120t单电极双塔式结构三工位可交替熔炼的恒熔速保护气氛电渣炉

本电渣炉是双塔式结构三工位可交替熔炼的恒熔速保护气氛电渣炉,其特征是配有两套塔式结构的可转动炉头部分,可分别在三个工位进行交替重熔冶炼。其特征在于,结合上述特征,再通过塔式机架、可转动和升降的炉头、电极调整装置、升降烟罩气氛保护、高精度称重系统、恒熔速自动控制系统技术的采用,最终满足大吨位高质量电渣锭的生产需求。优点：解决了现有技术所存在的大吨位高质量电极生产的困难,同时,还提高了电渣炉的有效利用率和生产的灵活性,提高生产效率。     

Effect of ESF preparations on different types of erythroblasts

A new method of quantitative (14)C-autoradiography was applied for evaluating possible effects of erythropoietin(ESF) on the DNA synthesis rate of differentiated erythroid murine bone marrow cells identified as proerythroblasts, basophilic and polychromatic erythroblasts...     

Comparative characteristics of some cultural and toxigenic properties of the Dendrodochium Bonorden and Myrothecium Tode ex Fr. representatives

The comparative study of sporulation intensity, change of medium pH, yield of biomass and ethanol soluble fraction (ESF) of extracellular metabolites as well as antibiotic and toxigenic properties of 106 fungi strains which were the potential producers of macrocyclic trichothecenes has been carried out under the conditions of stationary cultivation. It was shown that all the studied Dendrodochium strains were characterized by moderate growth, variations of biomass were within 3.5-4.5 g/l. Variations of ESF level in different strains were rather essential (from 8 to 241.6 mg/l). High antibiotic activity correlated with high or moderate toxicity (on the basis of rabbit skin test) in most cases. Dendrodochium strains with intensive sporulation were as a rule characterized by high efficiency of toxin production (40% of studied strains) and only 3 strains (5.5%) with low level of sporulation were characterized by high rate of toxin production. The toxigenic activity for Myrothecium cinctum, M. commune and M. ukrainicum has been shown for the first time. The toxigenic activity of the studied strains depending on the source of isolation and possible correlative connections between sporulation, toxin formation and other properties are discussed.     

Ausmelt炉镍熔炼合理渣型的研究

金川集团公司沉降电炉弃渣有价金属含量高且熔化温度高。采用SEM-EDS与XRD确定了镍和铜在渣中的主要损失形式为夹杂或悬浮。测定了以Ausmelt熔炼渣为基础的半合成渣的熔化温度,研究了Fe/SiO2及CaO含量对半合成渣熔化温度的影响。结果表明,当Fe/SiO2=0.9～1.0且CaO含量为6%～10%时,渣的熔化温度明显降低,为Ausmelt炉镍熔炼工艺参数的优化提供参考。     

A method for measuring the presampled MTF of digital radiographic systems using an edge test device

The modulation transfer function (MTF) of radiographic systems is frequently evaluated by measuring the system's line spread function (LSF) using narrow slits. The slit method requires precise fabrication and alignment of a slit and high radiation exposure. An alternative method for determining the MTF uses a sharp, attenuating edge device. We have constructed an edge device from a 250-microm-thick lead foil laminated between two thin slabs of acrylic. The device is placed near the detector and aligned with the aid of a laser beam and a holder such that a polished edge is parallel to the x-ray beam. A digital image of the edge is processed to obtain the presampled MTF. The image processing includes automated determination of the edge angle, reprojection, sub-binning, smoothing of the edge spread function (ESF), and spectral estimation. This edge method has been compared to the slit method using measurements on standard and high-resolution imaging plates of a digital storage phosphor (DSP) radiography system. The experimental results for both methods agree with a mean MTF difference of 0.008. The edge method provides a convenient measurement of the presampled MTF for digital radiographic systems with good response at low frequencies.     

Erythropoiesis inhibiting factor(s) (EIF). The specificity and toxicity of urinary EIF studied in vivo and in vitro

The specificity and toxicity of the urinary erythropoiesis inhibiting factor (EIF) has been tested both in vivo and in vitro. When EIF was given to ESF stimulated erythropoietically suppressed polycythaemic mice and to mice at maximal endogenous erythropoietic stimulation, a reduction of the erythroid bone marrow cells, the erythropoietic 3H-TdR L.I. and the total number of bone marrow cells were observed. No effect was seen on the myelopoietic bone marrow cells. An unspecific toxic effect was unlikely, since addition of EIF did not alter the proliferation of lymphoblastic cells nor change the glucose utilization of bone marrow cells in vitro. Neither did the amount of dead bone marrow cells increase after being incubated with EIF for 72 h. The results indicate that the urinary EIF is a non-toxic, cell specific inhibitor on erythropoiesis.     

Molecular phylogenetics and the evolution of antarctic notothenioid fishes

The monophyly of the antarctic fish suborder Notothenioidei and the monophyly of its earliest family the Bovichtidae have been investigated with 12S and 16S mitochondrial DNA sequences. New data from Cottoperca, Pseudaphritis, Harpagifer and several outgroups, in addition to available sequences, show that the bovichtids are paraphyletic. Pseudaphritis is the sister group of all the non-bovichtid notothenioids. The same results are found from two independent genetic markers, the nuclear 28S rDNA and the 12S and 16S mitochondrial rDNA. This reliably refutes a previous hypothesis that placed Pseudaphritis as the sister group of all the remaining notothenioids (including Cottoperca and Bovichtus). Bootstrap analyses show that the Notothenioidei are monophyletic (although members of the suborder Trachinoidei have not been surveyed). Subsequent data from hemoglobin composition confirm the present relationships. After discussions between members of the European Science Foundation (ESF) network during its last two meetings, we point out here some fundamental aspects of comparative biology to improve understanding between the physiologist community and phylogeneticists. The most important points are differences in how the concept of homology is used and differences in the consideration of adaptation. When adaptation is evoked or questioned, endless speculations and untestable scenarios are often developed. We strongly advocate the use of phylogenetic trees for testing hypotheses of adaptation (through multiple character mapping). Such a "research program" in comparative biology has the power to improve knowledge because it can potentially lead to new experiments for testing adaptive hypotheses.     

Changing the relative amplitudes of wave packets to induce nonlocal effects

The short- and long-term effects of an elemental diet in children with acute Crohn's disease were compared with those of prednisolone in historical controls. Clinical remission was induced in 25 of 30 and in 18 of 28 episodes treated for six weeks with an elemental diet and prednisolone. Patients with proximal disease had longer remission after treatment with an elemental diet (p < 0.05) than did patients with colonic disease after treatment with prednisolone (p < 0.01). Disease activity index score improved in both groups compared with the pretreatment scores (p < 0.05). However, the improvement in the elemental diet group was significantly better than in the prednisolone group (p < 0.001). Changes in linear growth were better after treatment with an elemental diet compared with steroids (p < 0.001). Serum albumin and haematocrit concentrations all improved significantly in the children treated with an elemental diet (p < 0.001) but not in those treated with steroids. Thus an elemental diet was better than prednisolone in proximal disease and confirmed improved growth and nutritional status.     

Anxiety and hostility to an "outsider," as moderated by low perceived power.

The hostile and anxious responses of young adults to an immigrant (vs. native-born) stranger were examined as a function of participants' self-perceived power. In Studies 1 and 2, individuals with low perceived social power (males, in particular) showed high anxiety toward an "outsider" but more so if that individual was an immigrant (and thus posed an ambiguous threat to their position in the hierarchy). In Study 3, young adult males competed on a reaction time test with an immigrant or native-born rival. With immigrant rivals, males with low perceived social power showed relatively high aggression toward an immigrant rival and derogation of the rival's formidability; however, they showed a more deferential pattern with native-born rivals. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

炉甘石中ZnCO_3,ZnO,PbCO_3,Fe_2O_3,(CaCO_3+MgCO_3)含量测定的研究

（１）以氨水（１＋４）溶解样品，用ＸＯ作指示剂，ＥＤＴＡ滴定，测定ＺｎＣＯ３含量。（２）以１５％的硫酸铵溶解样品，用ＸＯ作指示剂，ＥＤＴＡ滴定，测定（ＺｎＣＯ３＋ＺｎＯ）含量。（３）以１５％的氯化铵溶液溶解样品，用ＥＢＴ作指示剂，ＥＤＴＡ滴定，测定（ＺｎＣＯ３＋ＺｎＯ＋ＣａＣＯ３＋ＭｇＣＯ３）含量。（４）以１６％的乙酸铵溶液溶解样品，以ＸＯ作指示剂，ＥＤＴＡ滴定，测定（ＰｂＣＯ３＋ＺｎＣＯ３＋ＺｎＯ）含量。（５）以稀盐酸溶解样品，用磺基水杨酸作指示剂，ＥＤＴＡ滴定，测定Ｆｅ２Ｏ３含量。     

Kinetic mechanism of metallo-beta-lactamase L1 from Stenotrophomonas maltophilia

The reaction of nitrocefin with metallo-beta-lactamase L1 from Stenotrophomonas maltophilia was studied using rapid-scan and stopped-flow ultraviolet-visible (UV-vis) studies in an effort to discern the kinetic mechanism used by L1 to hydrolyze penicillins and cephalosporins. Rapid-scan and stopped-flow UV-vis studies of nitrocefin hydrolysis by L1 identified three species: (1) the substrate (nitrocefin) displayed an absorbance peak at 390 nm (epsilon = 11 500 M(-1) cm(-1)) that decreased during the reaction with a rate constant of 170 +/- 30 s(-1); (2) the product (hydrolyzed nitrocefin) displayed an absorbance peak at 485 nm (epsilon = 17 420 M(-1) cm(-1)) that increased during the reaction with rate constant of 40 +/- 1 s(-1); and (3) an intermediate displayed an absorbance peak at 665 nm (epsilon = 32 000 M(-1) cm(-1)) that increased initially with a rate constant of 190 +/- 3 s(-1) and then decreased with a rate constant of 38 +/- 2 s(-1). Single-turnover experiments demonstrated that there were no pre-steady-state bursts in the reaction of L1 with nitrocefin; moreover, the progress curves could be fit to a kinetic mechanism that includes the formation of a transient intermediate by using KINSIM and the rate constants given above. Progress curves from experiments conducted at different reaction conditions or with a different substrate could also be fit to the proposed kinetic mechanism. The evidence for the presence of an intermediate along with kinetic simulations supports a hydrolytic mechanism for L1 that involves an intermediate whose breakdown is rate-determining.     

Further evidence that naloxone acts as an inverse opiate agonist: implications for drug dependence and withdrawal

To test if naloxone behaved as an inverse agonist rather than as an antagonist we evaluated its responses in guinea-pig ilea with and without morphine (480 nM, 24 h). In control ilea, naloxone (100 nM) had no effect. In morphine-treated ilea, naloxone as a bolus, but not as an infusion, elicited an abstinence response. Preadministration of naloxone blocked the response to subsequent administrations. Similarly, naloxone failed to produce an abstinence response in ilea pretreated with kappa compounds (bremazocine, U50488 or xorphanol 100 nM) or with kinase inhibitors (H7 or H8 30 microM). These findings can be interpreted in the light of the two-state receptor model if naloxone behaves as an inverse agonist: Incubation with morphine increased the active state of receptors making them susceptible to the inverse agonist (naloxone); exposure to naloxone favored the inactive conformation making them insensitive to further administration of naloxone; kappa compounds behaved as antagonists preventing the response to naloxone; and kinase inhibitors interfered with the active conformation making the system insensitive to naloxone. According to this model, dependence can be viewed as an overexpression of the active receptors and withdrawal as an abrupt change from the active to the inactive state.