bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of the selective PAF antagonist SM‐10661 on an asthmatic model. 1. Effect on passive anaphylactic bronchoconstriction in guinea pigs
Authors: Uchida Masako , Imanishi Noriaki , Sugasawa Toshinari , Morooka Shigeaki
Published: February 2007

The effect of SM‐10661, a selective antagonist of platelet‐activating factor (PAF), on passive anaphylactic bronchoconstriction was examined in guinea pigs. A challenge of ovalbumin to passively sensitized guinea pigs induced bronchoconstriction, which peaked at 4 min. When SM‐10661 was administered intravenously 2 min before ovalbumin challenge, bronchoconstriction was inhibited dose‐dependently with an ID50 of 68 mg/kg. In guinea pigs pretreated with 15 μg/kg mepyramine which is a suboptimal dose, antigen‐induced bronchoconstriction peaked at 4–6 min, but was inhibited by SM‐10661 with an ID50 of 21 mg/kg. When guinea pigs were pretreated intravenously with 2.5 mg/kg mepyramine, 1 mg/kg indomethacin and 0.01 mg/kg propranolol, the antigen‐induced bronchoconstriction peaked at 6 min. SM‐10661 inhibited the response with an ID50 of 45 mg/kg. Histamine‐ and leukotriene D4‐induced bronchoconstrictions were unaffected by up to 100 mg/kg SM‐10661. Ovalbumin challenge of minced lungs from passively sensitized guinea pigs triggered the release of leukotrienes and histamine. SM‐10661 had no effect on the antigen‐induced release of peptide leukotrienes or histamine up to 10−4 M. These results indicate that SM‐10661 may be a useful tool to investigate the role of PAF in antigen‐induced anaphylactic bronchoconstriction.
Effect of platelet‐activating factor antagonist BN 52063 on the nephrotoxicity of cisplatin
Authors: Pavão dos Santos Oscar F. , Boim Mirian A. , Barros Elivo J. G. , Pirotzky Eduardo , Braquet Pierre , Schor Nestor
Published: February 2007

Cisplatin (DDP) is an effective anticancer agent that has been successfully applied against various solid tumors. However, DDP commonly causes nephrotoxicity. We observed that DDP led to significant alterations in renal microcirculation when administered to Munich‐Wistar rats, with a concomitant decrease in single nephron glomerular filtration rate due to reduction in glomerular plasma flow and transcapillary hydraulic pressure difference. BN 52063, a platelet‐activating factor antagonist, caused a striking change in acute renal failure induced by DDP leading toward normalization of all parameters of renal function. The results suggest that BN 52063 could be used as a novel drug to control DDP nephrotoxicity.
Significance of platelet‐activating factor in mesenteric ischemia‐reperfusion
Authors: Filep János , Braquet Pierre , Mózes Tibor
Published: February 2007

Reperfusion of the ischemic mesenterium is frequently followed by acute circulatory collapse. This review focuses on the possible role of platelet‐activating factor (PAF) in ischemia‐induced damage. It provides evidence that (i) PAF concentrations are elevated in the mesenteric circulation following temporary ischemia; (ii) administration of exogenous PAF into the superior mesenteric vein mimics many events observed during reperfusion; and (iii) pretreatment of the experimental animals with specific PAF receptor antagonists prevent the circulatory collapse. These findings suggest that PAF may play an important role in the development of circulatory collapse caused by mesenteric ischemia‐reperfusion.
Hypoxia, PAF, and necrotizing enterocolitis
Authors: Caplan Michael S. , Sun Xiao‐Ming , Hsueh Wei
Published: February 2007

Necrotizing enterocolitis (NEC) is an important neonatal disease with a high mortality rate. The pathophysiology is unclear but epidemiologic studies suggest that hypoxia and infection are important risk factors. In this review we discuss the effect of hypoxia and platelet‐activating factor (PAF) on intestinal blood flow and intestinal necrosis, and implicate PAF as an important mediator in hypoxia‐induced intestinal injury. Finally we provide evidence that PAF may be important in neonatal NEC.
Antagonism of platelet‐activating factor in isolated rat colon: Possible mechanism
Authors: Tokumura Akira , Yube Nobuyuki , Terao Motonori , Tsukatani Hiroaki
Published: February 2007

The contractions of three different regions of rat colon in response to platelet‐activating factor (PAF) were compared. The ascending colon was found to be the most responsive. The slow contraction of the ascending colon induced by PAF was dependent on external Ca2+. CV‐3988, a structural analog of PAF, slowly induced irreversible inhibition of PAF‐induced contraction, whereas FR‐900452, which is structurally unrelated to PAF, caused rapid reversible inhibition of PAF‐induced contraction. No inhibitory effects of CV‐3988 were observed when the strip was washed with Tyrode's solution containing 1% bovine serum albumin (BSA). The results suggest that PAF and CV‐3988 penetrate slowly into the outer half of the lipid bilayer of plasma membranes of cells in isolated rat colon, and then rapidly diffuse laterally to associate firmly with specific binding sites.
Molecular heterogeneity of platelet‐activating factor (PAF) in rat glandular stomach determined by gas chromatography/mass spectrometry. PAF molecular species changes upon water‐immersion stress
Authors: Sugatani Junko , Fujimura Kazuyo , Miwa Masao , Satouchi Kiyoshi , Saito Kunihiko
Published: February 2007

The molecular heterogeneity of 1‐alkyl‐2‐acetyl‐sn‐glycero‐3‐phosphocholine (alkylacetyl‐GPC) and 1‐acyl‐2‐acetyl‐sn‐glycero‐3‐phosphocholine (acylacetyl‐GPC) in normal rat glandular stomach was studied by gas chromatography/mass spectrometry (GC/MS) and tandem mass spectrometry. The percentage compositions of the molecular species of 1‐alkyl‐2‐acetyl‐GPC and 1‐acyl‐2‐acetyl‐GPC in the antrum were, respectively. 1‐alkyl [16∶0 (34%) and 18∶0 (66%)]‐2‐acetyl‐GPC and 1‐acyl [16∶0 (60%), 18∶0 (14%) and 18∶1 (26%)]‐2‐acetyl‐GPC. The alkyl chain composition of 1‐alkyl‐2‐acyl‐GPC was quite different from that of 1‐alkyl‐2‐acyl‐GPC in both the antrum and corpus, demonstrating a high degree of selectivity of alkyl chain utilization in PAF biosynthesis. The amount of 1‐acyl‐2‐acetyl‐GPC was much greater than that of 1‐alkyl‐2‐acetyl‐GPC. The molecular heterogeneity of 1‐alkyl‐2‐acetyl‐GPC and 1‐acyl‐2‐acetyl‐GPC in the corpus was similar to that in the antrum. Water‐immersion stress affected not only the amount of 1‐alkyl‐2‐acetyl‐GPC and 1‐acyl‐2‐acetyl‐GPC, but also their molecular heterogeneity in the antrum and corpus. Whereas the amounts of 1‐hexadecyl‐2‐acetyl‐GPC and 1‐acyl [16∶0, 18∶0 and 18∶1]‐2‐acetyl‐GPC decreased markedly (to less than one‐fifth) in the antrum after such stress for 1 hr, the amount of 1‐octadecyl‐2‐acetyl‐GPC increased markedly (up to 4‐fold) in the corpus and severe lesions were observed after stress for 7 hr. The changes may be associated with the pathogenicity of gastric ulcers.
Platelet‐activating factor and granulocyte‐mediated oxidative stress. Strategy forin vivo oxyradical visualization
Authors: Suematsu Makoto , Tsuchiya Masaharu
Published: February 2007

Platelet‐activating factor (PAF) and leukotriene B4 are potent lipid mediators of endothelium‐granulocyte interaction which results in granulocyte‐dependent increased microvascular permeability. The specific mechanism by which PAF induces granulocyte‐mediated endothelial injury has not been fully investigated. Digital imaging photonic intensified microscopy has revealed that PAF effectively induces granulocyte‐mediated oxidative stress on microvascular beds. The method has made it possible to visualize luminol‐dependent photonic burst released from PAF‐treated microvascular beds in the rat mesentery. The photonic activities clearly corresponded to the localization of sticking granulocytes in post‐capillary venules. By contrast, no significant chemilumigenic response could be detected in the leukotriene B4‐induced activation of endothelium‐granulocyte interactionin vivo. The present findings suggest that oxygen radicals are not prerequisites for granulocyte adhesion in the microcirculation and provide evidence for a dissociation ofin vivo granulocyte function between leukotactic and oxidative activation in leukotriene B4‐induced microvascular changes.
Involvement of platelet‐activating factor (PAF) in septic shock and priming as indicated by the effect of hetrazepinoic PAF antagonists
Authors: Heuer Hubert O.
Published: February 2007

Pharmacological data obtained with hetrazepinoic platelet‐activating factor (PAF) antagonists, such as apafant (WEB 2086) and bepafant (WEB 2170), indicate a role for PAF in septic shock and in the priming process. The effect of PAF antagonists in different models of shock states favors a role for PAF in endotoxin associated lethality, activation of inflammatory blood cells with release of mediators, cardiovascular failure and increased vascular permeability, and in the development of shock organs and organ failure. The priming process (e.g., by endotoxin or tumor necrosis factor) towards an increased susceptibility towards minute amounts of PAF has to be taken into account when considering the pathophysiological significance of PAF underin vivo conditions and in septic shock.
Effect of the hetrazepinoic platelet‐activating factor antagonist bepafant (WEB 2170) in models of active and passive anaphylaxis in mice and guinea pigs
Authors: Heuer H. O.
Published: February 2007

The selective hetrazepinoic platelet‐activating factor (PAF) antagonist WEB 2170 (Bepafant) was used to study the pathophysiological role of PAF in several models of anaphylaxis in mice and guinea pigs. In actively sensitized mice, the PAF antagonist WEB 2170 (1.0–10 mg/kgp.o.) protected mice from anaphylactic death in a dosedependent manner when the anaphylactic response was potentiated by the beta‐receptor antagonist propranolol. When active anaphylaxis in guinea pigs was induced intravenously by 100 mg/kg ovalbumin (OA) in the presence of small doses of the antihistamine mepyramine, additional treatment with oral or intravenous WEB 2170 protected the guinea pigs from anaphylactic death. Also, the remaining anaphylactic bronchoconstriction and blood pressure changes (including anaphylactic hypotension) were attenuated. When guinea pigs were passively sensitized with a heterologous antibodyvia the tracheal route and then challenged by ovalbumin (100 mg/kgi.v.) 24 hr after sensitization in the presence of 0.003 mg/kgi.v. mepyramine, additional treatment with tracheal WEB 2170 at 0.1–1 mg/kg protected the guinea pigs dosedependently not only from anaphylactic death but also from a further decrease of respiratory flow and changes of blood pressure. Increased levels of PAF‐like activity (20–50 ng PAF/whole lung) were detected in lungs removed from antigen‐challenged animals. The results suggest a causative role for PAF in active and passive anaphylaxis.
Effect of a selective PAF antagonist SM‐10661 ((±)‐cis‐3,5‐dimethyl‐2‐(3‐pyridyl)thiazolidin‐4‐one HCl) on experimental disseminated intravascular coagulation (DIC)
Authors: Imanishi Noriaki , Komuro Yoshihiro , Morooka Shigeaki
Published: February 2007

Intravenous infusion of endotoxin (0.25 mg/kg/hr for 4 hr) was shown to induce disseminated intravascular coagulation (DIC) in rats, which resulted in hypofibrinogenemia, prolongation of prothrombin (PT) and partial thromboplastin time (PTT), thrombocytopenia, and elevated levels of fibrinogen/fibrin degradation products (FDP). Oral administration (100 mg/kg) of the selective PAF antagonist, SM‐10661 ((±)‐cis‐3,5‐dimethyl‐2‐(3‐pyridyl)thiazolidin‐4‐one HCl), counteracted the changes caused by the endotoxin. Intravenous infusion of SM‐10661 (6mg/kg bolus 2 min before endotoxin infusion+6 mg/kg/hr for 4 hr infusion) also counteracted DIC. When suboptimal doses of gabexate mesilate, a synthetic protease inhibitor (3 mg/kg i.p.), and SM‐10661 (2 mg/kg bolus + 2 mg/kg/hr for 4 hr infusion) were administered concomitantly, hematological parameters improved. The results suggest that PAF may play a role in the pathogenesis of DIC, and that together with the results already reported for other PAF antagonists, SM‐10661 may be useful in the treatment of DIC.
Effect of PAF‐acether antagonists on active anaphylactic mouse paw edema
Authors: Amorim Claudia Zuany , de Oliveira Henriques Maria das Graças Muller , Weg Vivian Baseches , Balão Cordeiro Renato Sérgio , Vargaffig B. Boris
Published: February 2007

A new model of active anaphylactic reaction in mice was developed. The edematogenic reaction appeared 5 min after the intraplantar injection of ovalbumin, peaked at 30 min after the antigenic challenge, and decreased there‐after. Using the non‐steroidal, anti‐inflammatory agents indomethacin and aspirin, we found that cyclooxygenase products do not participate in the reaction. In contrast, vasoactive amines appear to be involved, because meclizine and methysergide reduced the edema. Dexamethasone, BW755C, LY 171883 and WEB 2170 effectively interfered with the edematogenic reaction, which suggests that lipid mediators such as leukotrienes and PAF play a role in the active anaphylactic response.
Pooling of blood in postischemic shock is modulated by platelet‐activating factor (PAF)
Authors: Sagach V. F. , Dmitrieva A. V. , Braquet P.
Published: February 2007

In experiments on dogs,i.v. administration of platelet‐activating factor (PAF) (500 ng/kg) was shown to induce hypotension which, apart from decreased myocardial contractility, was characterized by blood pooling in veins (82.6±6.8 mL/kg). This was accompanied by restriction of venous return to the heart and reduction of cardiac output (CO). During postischemic shock the cardio‐ and hemodynamic disturbances were similar to those induced byi.v. administration of PAF. In the postischemic shock model, preliminary blockage of PAF receptors with the PAF receptor antagonist BN 52021 (6 mg/kg,i.v.) significantly decreased the amount of blood pooled in shock from 38.7±5 to 18.3±2 mL/kg (p<0.01). Simultaneously, the reduction of CO and blood pressure, induced by reperfusion of the continuously ischemized tissues of a rear limb, was less significant in pretreatedvs. the nontreated group. The data suggest that PAF may be involved in postischemic blood pooling and that PAF antagonists could be used to correct postischemic cardio‐ and hemodynamic disturbances.
Induction of platelet‐activating factor in mice by intravenous administration of a neutral fraction of bakers' yeast mannan
Authors: Mikami Takeshi , Fukushi Ken , Ishitani Miki , Ishitani Kouki , Suzuki Shigeo , Suzuki Masuko
Published: February 2007

A neutral subfraction of mannan of bakers' yeast (WNM) was found to show a lethal effect in mice when administered intravenously. Symptoms caused by intravenous (i.v.) administration of WNM resembled those resulting from the administration of platelet‐activating factor (PAF). CV‐3988 and ONO‐6240, selective PAF antagonists, prevented hypotension and death caused by the administration of WNM or PAF. A β‐adrenoceptor agonist was shown to prevent death caused by WNM, whereas propranolol increased the lethal activity of WNM. Intravenous administration of WNM into mice produced PAF in gall bladder fluid which was determined by platelet aggregation assay. The findings indicate that WNM is able to induce PAF in mice and that the resultant PAF may participate in the WNM‐induced lethal activity observed in mice.
Hexadecylphosphocholine: Preclinical and the first clinical results of a new antitumor drug
Authors: Unger Clemens , Eibl Hansjörg
Published: February 2007

Dose‐response studies on cytotoxic alkyl lysophospholipids with various chemical structures revealed that a long alkyl chain and a polar group are essential for antitumor activity. The combination of both the long alkyl chain and a phosphocholine group thus results in alkyl phosphocholines. Preclinical, studies with hexadecylphosphocholine (He‐PC) as a representative compound indicate distinct antineoplastic activity on leukemia cells of human origin. He‐PC is highly effective in inhibiting the growth of chemically induced rat mammary carcinomas. Even more striking is the fact that a high percentage of the tumors regressed completely. In a clinical phase I trial on breast cancer patients with local recurrences, topically applied He‐PC resulted in regression of skin metastases. A phase II trial for topical treatment and a phase I trial for orally applied He‐PC have been initiated to further evaluate the antitumoral activity of this new compound.
Comparison of selective cytotoxicity of alkyl lysophospholipids
Authors: Vogler W. R. , Olson A. C. , Okamoto S. , Shoji M. , Raynor R. L. , Kuo J. F. , Berdel W. E. , Eibl H. , Hajdu J. , Nomura H.
Published: February 2007

Alkyl lysophospholipids have been shown to be cytooxic to a number of neoplastic tissues. One, ET‐18‐OCH3, has been used to selectively purge leukemic cells from mixtures with normal marrow progenitor cells,in vitro andin vivo. We have measured the 50% inhibitory (IC50) effect of a series of ether, lipids (EL) on leukemic cells (HL60, K562, Daudi, KG‐1, KG‐1a) and normal marrow progenitor cells. Cells were incubated with varying concentrations of EL for 4 hr and assayed for viability, [3H]thymidine incorporation and clonogenicity in semi‐solid media. The effect on protein kinase C (PKC) activity was assayed for each compound. Compounds tested included three glycerophosphocholine analogs‐ET‐18‐OCH3, ET‐16‐NHCOCH3, and BM 41.440. In addition, a lipoidal amine, CP 46665, an ethyleneglycolphospholipid, AEPL, and four single chain alkylphosphocholine analogs, HePC2, HePC3, HePC4 and HePC6 were also tested. During the period of incubation, the cells remained viable (>70%) as judged by trypan blue dye exclusion. The glycerophosphocholines were the most active and showed the highest therapeutic index. The lipoidal amine was active, but toxic to normal marrow progenitor cells. The ethyleneglycolphospholipid was active against HL60, but not against the other cell lines. The single chain alkylphosphocholine analogs were less active. All of the compounds inhibited PKC activity; however, the glycerophosphocholines were the most inhibitory.
Gas‐liquid chromatographic analysis of monoglycerides as their trimethylsilyl ether derivatives
Authors: Wood R. D. , Raju P. K. , Reiser Raymond
Published: February 2007

A quantitative method is described for the rapid gas‐liquid chromatographic analysis of monoglycerides of long chain fatty acids as their trimethylsilyl (TMS) ether derivatives. The TMS derivatives are formed rapidly and quantitatively at room temp without isomerization. The TMS derivatives of 1‐ and 2‐monoglycerides may be separated on polyester columns, which can also be used for the analysis of methyl esters. A mixture of the 1‐ and 2‐isomers of monopalmitin and monoolein was quantitatively analyzed. A mixture of monocaprin, monolaurin, monomyristin, monopalmitin and monosterin was also analyzed. A mixture of 1‐monostearin, 1‐monoolein and 1‐monolinolein was also resolved. The analyses were carried out on packed and large bore capillary columns of diethylene glycol succinate polyester (DEGS) and Apiezon L. Capillary columns that required the use of a splitter were nonquantitative, resulting from what appeared to be fractionation at the splitter. Acid conditions, including those provoked by the use of phosphoric acid stabilized polyesters, cleaved the TMS derivatives to yield the original hydroxy compound.
Branched chain fatty acids and sulfonated derivatives
Authors: Ault W. C. , Micich T. J. , Stirton A. J. , Bistline R. J.
Published: February 2007

Several 2‐alkyl fatty acids containing 18舑21 carbon atoms, were synthesized by tertiary butyl peroxide catalyzed addition of linear aliphatic carboxylic acids to normal terminal olefins. The products obtained in 35舑70% yields were purified by fractional distillation. The acids were sulfonated with sulfur trioxide dioxane adduct and isolated as the disodium salts in 60舑80% yields.

urn:x-wiley:0003021X:media:aocs0233:equation:aocs0233-math-0001

Surface active properties of the sodium salts of the 2‐alkyl carboxylic acids and the corresponding sulfonated products were evaluated. Good wetting properties were observed for those sulfonated acids where the hydrophilic portion of the molecule was equidistant from the ends of the hydrocarbon chain.
Alkaline isomerization of methyl crepenynate
Authors: Mikolajczak K. L. , Bagby M. O. , Wolff I. A.
Published: February 2007

Methyl crepenynate (methyl‐cis‐9‐octadecen‐12‐ynoate) is readily isomerized by potassium hydroxide in ethylene glycol to an 8,10,12‐octadecatrienoic acid in good yield. A reaction carried out at 120C for 1 hr in 10% base is sufficient to convert the nonconjugated enyne system completely to conjugated triene systems.
Components of the hardening flavor present in hardened linseed oil and soybean oil
Authors: Keppler J. G. , Schols J. A. , Feenstra W. H. , Meijboom P. W.
Published: February 2007

The characteristic hardening flavor which develops in hardened linseed and soybean oils during storage has been coned from hardened linseed oil by stripping with nitrogen. After separating the volatile substances by adsorption chromatography on silica, the fraction containing the hardening flavor has been converted into 2,4‐dinitrophenylhydrazones (DNPHs) and separated by means of partition chromatography. On regeneration of the fractions of DNPSs obtained, the characteristic hardening flavor was observed in one specific band. Both by hydrogenation and by oxidation of the free carbonyl the carrier of the flavor was found to be an unsaturated aldehyde; however, not of the ॅ‐ॆ unsaturated type. Further separation of the regenerated carbonyls by means of gas‐liquid chromatography (GLC) points to a C9‐aldehyde. After synthesis of the 4‐,5‐ and 6‐cis‐ andtrans‐nonenals, comparison made it probable that the carrier of the hardening flavor is a mixture of 6‐cis and 6‐trans‐nonenal, the latter of which has the greatest share in the hardening flavor.

In order to confirm the location of the double bond in the carrier of the hardening flavor a recent isolation technique was applied. The volatile substances from hardened linseed oil were first separated via GLC. After conversion of the carbonyls in question into their DNPHs, the latter have been separated by means of thin‐layer chromatography (TLC). By means of IR‐analysis and oxidation with osmium tetroxide of the pure derivative, the principal carrier of the hardening flavor has been identified as 6‐trans‐nonenal.
Living with Multiple Endocrine Neoplasia Type 1: Decent Care‐Insufficient Medical and Genetic Information A Qualitative Study of MEN 1 Patients in a Swedish Hospital
Authors: Strømsvik Nina , Nordin Karin , Berglund Gunilla , Engebretsen Lars F. , Hansson Mats G. , Gjengedal Eva
Published: February 2007

This qualitative study explores how 29 Swedish patients with Multiple Endocrine Neoplasia type 1 (MEN1) experience living with the condition, appraisal of the clinical follow‐up program, and surveys their future expectations. The aim of this study is to build knowledge about this patient group in order to provide optimal care. The participants describe physical, psychological, and social limitations in their daily activities and how these limitations influence quality of life. Our findings indicate that a majority of patients have adjusted to their situation, describing themselves as being healthy despite physical symptoms and treatment. The participants received decent care in the clinical follow‐up program, ‐ however, greater effort should be put into patient information. These patients might benefit from genetic counseling. Health professionals involved should recognize their potential impact and influence on a patient's ability to adjust to these circumstances. Antonovsky's Sense of Coherence theory is used to discuss these findings.
The Effect of Disruptions During Counseling on Recall of Genetic Risk Information: The Case of Cystic Fibrosis
Authors: Dillard James Price , Shen Lijiang , Tluczek Audrey , Modaff Peggy , Farrell Philip
Published: February 2007

Genetic counseling is a communication process with two main functions: information provision and supportive counseling. The information transmission function may be compromised by disruptions that occur during counseling. At least two mediators are possible: (a) disruptions may interfere with memory by creating distractions and divided attention during encoding or (b) disruptions may degrade the flow of interaction which requires that participants engage in conversation repair rather than the task at hand. This study examined both alternatives in a group of parents (N=20 families, 40 individual parents) whose infant had received a newborn screening for cystic fibrosis (CF). Upon arrival at the hospital, each parent completed a questionnaire designed to assess his or her knowledge of CF. Their interaction with the genetic counselor was videotaped and coded for the presence of disruptions. Six weeks after the counseling, parents again completed the knowledge measure. The data showed a direct negative effect for disruptions during counseling on memory for CF‐related risk information six weeks later. Disruptions also produced the anticipated effect on conversation, but counter to expectations, interruptions of conversation flow was positively associated with knowledge at time 2.
Assessing the Informational Needs of Adolescents with a Genetic Condition: What Do They Want to Know?
Authors: Szybowska Marta , Hewson Stacy , Antle Beverley J. , Babul‐Hirji Riyana
Published: February 2007

Adolescence is a period of challenges that can be more stressful for someone with a genetic condition. The purpose of this descriptive pilot study was to assess the informational needs of adolescents with a genetic condition. To our knowledge, this is the first study that has attempted to identify these needs. A convenience sample of adolescents between 12–19 years of age with either phenylketonuria or congenital adrenal hyperplasia and who had not previously received genetic counseling was recruited. Recruitment ended once the themes were saturated (n=17). A twenty item open/close‐ended questionnaire was used to assess participants’ knowledge of their genetic condition, what they wanted to know about their condition and in what manner. Almost all of the adolescents knew the name and genetic basis of their condition while most were aware of the risk of recurrence in a future pregnancy. Parents and doctors respectively, were identified as the primary and secondary sources of genetic information. Despite their evolving independence, almost all of the participants favoured receiving medical information with their parents present. The majority of participants felt that patients should begin receiving genetic information before the age of 12 years. Thematic analysis revealed that adolescents wanted to understand the science behind their condition, how their condition affects them, and how to manage it. The results highlight (i) the importance that adolescents place on parental involvement in their medical care (ii) that adolescents would like information about the genetics of their condition at a much younger age than when they usually receive genetic counseling and (iii) the benefits that can be gained by this patient population from receiving genetic counseling.
Characterization of the Practice and Attitudes of Genetic Counselors with Doctoral Degrees
Authors: Atzinger Carrie L. , Blough‐Pfau Ruthann , Kretschmer Laura , Huether Carl A. , Johnson Judith A. , Warren Nancy Steinberg
Published: February 2007

Potential advantages and disadvantages of doctoral training in genetic counseling have been debated. In this study, individual interviews were conducted to characterize the practice and attitudes of genetic counselors who have achieved doctoral degrees in any field. Participants (N=31) were more likely to spend time in research and less likely to spend time in clinic than genetic counselors in general. Advantages identified by participants were consistent with theorized advantages, and included increased knowledge, wider research roles, additional opportunities and greater respect. Disadvantages identified by participants focused more on individual perspectives than previously theorized profession‐wide disadvantages. These included increased time commitment and decreased patient contact. The attitudes of participants towards the development of doctoral training in genetic counseling were generally positive. The results suggest that doctoral training in genetic counseling would have more benefits than drawbacks for individuals pursuing this degree.
Seismic structure of the Endeavour Segment, Juan de Fuca Ridge: Correlations with seismicity and hydrothermal activity
Authors: Van Ark E. M. , Detrick R. S. , Canales J. P. , Carbotte S. M. , Harding A. J. , Kent G. M. , Nedimovic M. R. , Wilcock W. S. D. , Diebold J. B. , Babcock J. M.
Published: February 2007

Multichannel seismic reflection data collected in July 2002 at the Endeavour Segment, Juan de Fuca Ridge, show a midcrustal reflector underlying all of the known high‐temperature hydrothermal vent fields in this area. On the basis of the character and geometry of this reflection, its similarity to events at other spreading centers, and its polarity, we identify this as a reflection from one or more crustal magma bodies rather than from a hydrothermal cracking front interface. The Endeavour magma chamber reflector is found under the central, topographically shallow section of the segment at two‐way traveltime (TWTT) values of 0.9–1.4 s (∼2.1–3.3 km) below the seafloor. It extends approximately 24 km along axis and is shallowest beneath the center of the segment and deepens toward the segment ends. On cross‐axis lines the axial magma chamber (AMC) reflector is only 0.4–1.2 km wide and appears to dip 8–36° to the east. While a magma chamber underlies all known Endeavour high‐temperature hydrothermal vent fields, AMC depth is not a dominant factor in determining vent fluid properties. The stacked and migrated seismic lines also show a strong layer 2a event at TWTT values of 0.30 ± 0.09 s (380 ± 120 m) below the seafloor on the along‐axis line and 0.38 ± 0.09 s (500 ± 110 m) on the cross‐axis lines. A weak Moho reflection is observed in a few locations at TWTT values of 1.9–2.4 s below the seafloor. By projecting hypocenters of well‐located microseismicity in this region onto the seismic sections, we find that most axial earthquakes are concentrated just above the magma chamber and distributed diffusely within this zone, indicating thermal‐related cracking. The presence of a partially molten crustal magma chamber argues against prior hypotheses that hydrothermal heat extraction at this intermediate spreading ridge is primarily driven by propagation of a cracking front down into a frozen magma chamber and indicates that magmatic heat plays a significant role in the hydrothermal system. Morphological and hydrothermal differences between the intermediate spreading Endeavour and fast spreading ridges are attributable to the greater depth of the Endeavour AMC and the corresponding possibility of axial faulting.
Langmuir circulation driving sediment entrainment into newly formed ice: Tank experiment results with application to nature (Lake Hattie, United States; Kara Sea, Siberia)
Authors: Dethleff Dirk , Kempema E. W.
Published: February 2007

Langmuir circulation (Lc) was generated under freezing conditions in saltwater tank experiments through surface wind stress and cross‐waves interacting with subsurface return flow. Fine‐grained sediments distributed in the tank prior to frazil crystal formation were aligned in parallel streaks in Lc bottom convergence zones. Downwelling at Lc surface convergence zones aligned floating frazil in wind‐parallel rows, and individual crystals rotated on helical paths down to the tank bottom and up again to the surface. The crystals interacted with suspended particles in the water column, and with sediment on the tank bottom, preferentially collecting fine‐grained particles and enhancing their entrainment into new ice. Evidence includes higher sediment concentrations in ice and ice‐interstitial water (ice pore water) as compared to the tank water. Both tank ice and ice interstitial water contain more silt‐sized particles than tank water suspension load and tank bottom sediment. Sand is reduced in the ice, and clay is about the same concentration in all samples. This points to preferential entrainment of fine particles in newly formed ice supported by Lc‐driven circulation. Comparable results of Lc‐supported ice particle entrainment were found in Lake Hattie. Comparison of ice sediment from tank experiments run with Kara Sea material to ice particles from the natural Kara setting showed both types of ice sediment have very similar grain size distributions and mineralogical compositions. Results from experiments and nature help to better understand the potentially Lc‐driven entrainment of sediment into ice formed in shallow freezing waters.
On the solubility and diffusivity of the intrinsic point defects in germanium
Authors: Vanhellemont Jan , Śpiewak Piotr , Sueoka Koji
Published: February 2007

There is a strong interest to use germanium as an active device layer in deep sub-micron devices. This imposes similar stringent material and process requirements for germanium as for silicon. Lattice defect formation during crystal growth and device processing as well as dopant diffusion and activation are to a large extent controlled by the intrinsic point defects in the semiconductor. The properties of the vacancy and the self-interstitial in germanium are, however, not well known. The scarce available experimental data are combined with ab initio and molecular-dynamics calculations and other published simulation results. Based on this a best estimate is made for the formation and migration energies of the vacancy and the self-interstitial in germanium.
The surface structure of concentrated aqueous salt solutions
Authors: Sloutskin E. , Baumert J. , Ocko B. M. , Kuzmenko I. , Checco A. , Tamam L. , Ofer E. , Gog T. , Gang O. , Deutsch M.
Published: February 2007

The surface-normal electron density profile ρs(z) of concentrated aqueous salt solutions of RbBr, CsCl, LiBr, RbCl, and SrCl2 was determined by x-ray reflectivity (XR). For all but RbBr and SrCl2 ρs(z) increases monotonically with depth z from ρs(z)=0 in the vapor (z<0) to ρs(z)=ρb of the bulk (z>0) over a width of a few angstroms. The width is commensurate with the expected interface broadening by thermally excited capillary waves. Anomalous (resonant) XR of RbBr reveals a depletion at the surface of Br− ions to a depth of ∼10Å. For SrCl2, the observed ρs(z)>ρb may imply a similar surface depletion of Cl− ions to a depth of a few angstorms. However, as the deviations of the XRs of RbBr and SrCl2 from those of the other solutions are small, the evidence for a different ion composition in the surface and the bulk is not strongly conclusive. Overall, these results contrast earlier theoretical and simulational results and nonstructural measurements, where significant surface layering of alternate, oppositely charged, ions is concluded.
Electrical bistable behavior of an organic thin film through proton transfer
Authors: Tu Deyu , Shang Liwei , Liu Ming , Wang Congshun , Jiang Guiyuan , Song Yanlin
Published: February 2007

This letter reports the synthesis of an organic molecule N,N′-bis (salicylidene)-1,6-hexanaphthenediamine (BSH) and the study of its electrical properties. Reversible electrical bistable behavior was observed both in BSH organic thin film on indium tin oxide substrate and in a crossbar device fabricated via standard integrated circuit processing with this thin film. The proton transfer model, induced by a bias higher than the switch threshold voltage, was employed to explain the electrical bistable phenomenon. This electrical bistability of BSH molecules is a key property for potential applications in organic nonvolatile memories and programable switches.
Real-time observation of intramolecular proton transfer in the electronic ground state of chloromalonaldehyde: An ab initio study of time-resolved photoelectron spectra
Authors: do N. Varella Márcio T. , Arasaki Yasuki , Ushiyama Hiroshi , Takatsuka Kazuo , Wang Kwanghsi , McKoy Vincent
Published: February 2007

The authors report on studies of time-resolved photoelectron spectra of intramolecular proton transfer in the ground state of chloromalonaldehyde, employing ab initio photoionization matrix elements and effective potential surfaces of reduced dimensionality, wherein the couplings of proton motion to the other molecular vibrational modes are embedded by averaging over classical trajectories. In the simulations, population is transferred from the vibrational ground state to vibrationally hot wave packets by pumping to an excited electronic state and dumping with a time-delayed pulse. These pump-dump-probe simulations demonstrate that the time-resolved photoelectron spectra track proton transfer in the electronic ground state well and, furthermore, that the geometry dependence of the matrix elements enhances the tracking compared with signals obtained with the Condon approximation. Photoelectron kinetic energy distributions arising from wave packets localized in different basins are also distinguishable and could be understood, as expected, on the basis of the strength of the optical couplings in different regions of the ground state potential surface and the Franck-Condon overlaps of the ground state wave packets with the vibrational eigenstates of the ion potential surface.
Polarized Raman scattering of domain structures in polycrystalline lead zirconate titanate
Authors: Deluca Marco , Sakashita Tatsuo , Pezzotti Giuseppe
Published: February 2007

The intensity change upon crystal rotation of selected Raman modes of a lead-zirconate-titanate-based relaxor has been examined from both theoretical and experimental viewpoints. Periodic functions, representing intensity ratios between Raman bands as a function of crystal orientation, have been theoretically derived from the Raman tensor of both Ag and E phonon modes. Theoretical computations were compared with experimental data on a poled polycrystal and a discussion provided on reliability of different spectroscopic approaches for quantitative assessment of domain orientation.
Electron spin-resonance studies of conduction electrons in phosphorus-doped silicon nanocrystals
Authors: Sumida Kazuaki , Ninomiya Keiichi , Fujii Minoru , Fujio Kazuyoshi , Hayashi Shinji , Kodama Masafumi , Ohta Hitoshi
Published: February 2007

The properties of conduction electrons in P-doped Si nanocrystals embedded in insulating glass matrices have been studied by electron spin-resonance spectroscopy. For heavily P-doped samples, a broad conduction electron signal is observed at low temperatures. The width of the signal is found to be much broader than that of P-doped bulk Si crystals. The temperature dependence of the signal intensity obeys the Curie law even when the P concentration is very high. This suggests that in P-doped nanocrystals donor levels do not merge into the conduction band even at very high P concentration, and also provides evidence that Si nanocrystals smaller than a certain threshold size do not become metallic, at least when they are prepared under an equilibrium condition.
Effect of sintering temperature on the phase transition and dielectrical response in the relaxor-ferroelectric-system 0.5PZN–0.5PZT
Authors: Chang Li-Min , Hou Yu-Dong , Zhu Man-Kang , Yan Hui
Published: February 2007

Relaxor ferroelectrics of 0.5Pb(Zn1∕3Nb2∕3)O3–0.5Pb(Zr0.47Ti0.53)O3 (0.5PZN–0.5PZT) near the morphotropic phase boundary (MPB) were prepared using the conventional oxide mixing method. The influence of sintering temperature on the phase transition and dielectrical response in the relaxor-ferroelectric-system 0.5PZN–0.5PZT has been investigated. X-ray diffraction analysis indicated that the phase of the material changed from an initially rhombohedral structure to a MPB structure and then a tetragonal structure when the sintering temperature is increased from 900to1250°C. The corresponding grain size is enlarged from 1.1μm for predominantly rhombohedral to 2.5μm for more than 60% tetragonal, which obeys the common grain-growth law. The dielectric studies revealed that the indicator of the degree of diffuseness γ decreased with the increase of the sintering temperature from 900to1150°C, indicating that the dielectric relaxor behavior was weakened, while at high sintering temperature above 1250°C, γ increased subsequently, which was attributed to the Pb vacancy due to the formation of a pyrochlore phase. Raman analysis on the B-site cation order correlates well with the dielectric measurement results.
Analysis of strain relaxation in GaAs∕InGaAs∕GaAs structures by spectroscopy of relaxation-induced states
Authors: Chen J. F. , Chiang C. H. , Hsieh P. C. , Wang J. S.
Published: February 2007

Strain relaxation in GaAs∕In0.2Ga0.8As∕GaAs structures is investigated by analyzing relaxation-induced traps. Strain relaxation is shown to cause carrier depletion by the induction of a 0.53eV trap in the top GaAs layer, a 0.13eV trap in the InGaAs layer, and a 0.33eV trap in the neighboring lower GaAs layer. The 0.53eV trap which exhibits a logarithmic function of transient capacitance is attributed to threading dislocations. The 0.33eV trap exhibits an exponential transient capacitance, suggesting a GaAs point defect as its origin. Given its activation energy, it is assigned to the EL6 in GaAs, commonly considered to be Asi-VGa complexes. This trap and the 0.13eV trap are regarded as the same, since their energy difference is comparable to the optically determined conduction-band offset. The spatial location of this trap correlates with that of misfit dislocations. Accordingly, the production of this trap is determined from the mechanism of strain relaxation. A likely mode of strain relaxation is deduced from the locations of these traps.
Interphoton burst recurrence times: Single cell analysis in freely flowing solutions
Authors: Edel Joshua B. , deMello Andrew J.
Published: February 2007

The authors present a simple and direct analysis method for the discrimination between different cell populations in fluidic media. The methodology is based on analysis of single particle interphoton burst recurrence times and has potential use in high precision single cell sizing and counting applications. The approach requires registration of only a few hundred photons from single fluorescent particles to distinguish between different molecular populations. The technique is simple to implement and can be designed to extract information in real time within microfluidic environments.
Low dielectric loss BaNd2Ti5O14 thick films prepared by an electrophoretic deposition technique
Authors: Fu Zhi , Wu Aiying , Vilarinho P. M. , Kingon A. I. , Wördenweber R.
Published: February 2007

Ba Nd 2 Ti 5 O 14 (BNT) films 12–52μm thick were fabricated on platinum metallic foils by electrophoretic deposition (EPD). 52-μm-thick BNT film exhibits a dielectric constant and a loss tangent of 107 and 0.0006 (Q of 1600) at 1MHz, respectively. Variation in permittivity is less than 0.02% at a bias voltage ±8kV∕cm. Change of film permittivity with temperature (30–120°C) is below +58.5ppm∕°C, pointing to a good thermal stability. Preliminary microwave measurements indicate that the losses are not significantly increased up to the gigahertz regime. EPD derived BNT thick films on metallic foils are attractive candidates for microwave communication devices.
Defect reduction of selective Ge epitaxy in trenches on Si(001) substrates using aspect ratio trapping
Authors: Park J.-S. , Bai J. , Curtin M. , Adekore B. , Carroll M. , Lochtefeld A.
Published: February 2007

Defect-free germanium has been demonstrated in SiO2 trenches on silicon via Aspect Ratio Trapping, whereby defects arising from lattice mismatch are trapped by laterally confining sidewalls. Results were achieved through a combination of conventional photolithography, reactive ion etching of SiO2, and selective growth of Ge as thin as 450nm. Full trapping of dislocations originating at the Ge∕Si interface has been demonstrated for trenches up to 400nm wide without the additional formation of defects at the sidewalls. This approach shows great promise for the integration of Ge and/or III-V materials, sufficiently large for key device applications, onto silicon substrates.
Short-wavelength (λ≈3.05μm) InP-based strain-compensated quantum-cascade laser
Authors: Semtsiv M. P. , Wienold M. , Dressler S. , Masselink W. T.
Published: February 2007

The design and implementation of a short-wavelength quantum-cascade laser based on the strain-compensated In0.73Ga0.27As–In0.55Al0.45As–AlAs heterosystem on InP is described. Lasers with a reduced level of doping in the active region require a larger bias voltage and emit at shorter wavelength; the emission wavelength is 3.05μm at T≈80K. The lasers operate up to T≈150K and electroluminescence persists up to room temperature, where the peak position is close to 3.3μm. The short-wavelength limit of such lasers is evaluated based on the dependence of their maximum operation temperatures and on the probable energies of the indirect valleys in the active region.
Ethynyl (C2H): A major player in the chemical vapor deposition of diamond
Authors: Deák Peter , Kováts Antal , Csíkváry Peter , Maros István , Hárs György
Published: February 2007

In situ mass spectrometry of the near-surface composition—with special emphasis on radicals—has been carried out during diamond deposition from a microwave plasma in a CH4∕H2 mixture at 25 and 100mbars. The most abundant species in the former case are C2H2 and CH3, together giving 65% of the hydrocarbon content. At 100mbars, this value drops to 15%, while the C2H content rises to 76%. The factor of ∼8 increase in the C2H ratio is accompanied by a similar increase in the growth rate, indicating a major role of C2H in diamond growth.
High power continuous-wave green light generation by quasiphase matching in Mg stoichiometric lithium tantalate
Authors: Tovstonog Sergey V. , Kurimura Sunao , Kitamura Kenji
Published: February 2007

Single-pass second-harmonic generation of 7W continuous wave of 542nm radiation with 35.4% efficiency was achieved by quasiphase matching in periodically poled Mg-doped stoichiometric lithium tantalate at room temperature. The effects of laser beam quality and linewidth on the second-harmonic generation efficiency were investigated using a Yb-doped fiber laser.
Therapeutic effects of immunization with mutant superoxide dismutase in mice models of amyotrophic lateral sclerosis
Authors: Urushitani Makoto , Ezzi Samer Abou , Julien Jean-Pierre
Published: February 2007

There is emerging evidence for the existence of secretory pathways for superoxide dismutase (SOD1) mutants linked to amyotrophic lateral sclerosis (ALS) and for neurotoxicity of extracellular mutant SOD1. This evidence led us to test immunization protocols aiming to reduce the burden of extracellular SOD1 mutants in nervous tissue of mice models of ALS, by using bacterially purified recombinant SOD1 mutant protein as an immunogen. First, a vaccination was tested on a G37R
SOD1
mouse strain with late-onset disease exhibiting levels of mutant SOD1 protein at 4-fold higher than normal SOD1 levels. Repeated injections of adjuvant/SOD1 mutant with a final booster injection before symptoms at 6 months of age were effective in delaying disease onset and extending the life span of G37R
SOD1
mice by >4 weeks. Western blot analysis with a monoclonal antibody specific to mutant SOD1 forms provided evidence of clearance of SOD1 species in the spinal cord of vaccinated G37R
SOD1
mice. In contrast, this vaccination approach failed to confer significant protection in G93A
SOD1
mice with extreme overexpression of mutant SOD1. Nonetheless, a passive immunization through intraventricular infusion of purified anti-human SOD1 antibody with osmotic minipump succeeded in alleviating disease symptoms and prolonging the life span of G93A
SOD1
mice. From these results, we propose that immunization strategies should be considered as potential avenues for treatment of familial ALS caused by
SOD1
mutations.