Monitoring biosynthesis of wheat cell-wall phenylpropanoids in situ.

Lignins and suberins are complex plant cell-wall macromolecules that are composed mainly of phenylpropanoid residues derived from L-phenylalanine. Lignins and suberins are considered to be covalently linked to carbohydrates and to lipids, respectively. The bonding of these important structural materials within cell walls has never been established. By feeding specifically labeled [(13)C] ferulic acid over extended durations to seedlings of Triticum aestivum L. and by using solid-state carbon-13 nuclear magnetic resonance techniques, the major resonances due to specific carbons in the propanoid side chains of these cell-wall polymers have been identified in situ. The signals were found to differ significantly from those of synthetic lignins, which have usually been considered to be good approximations of natural lignin structure.

Antenatal dexamethasone treatment transiently alters diastolic function in the mouse fetal heart.

Endogenous glucocorticoid action is important in the structural and functional maturation of the fetal heart. In fetal mice, although glucocorticoid concentrations are extremely low before E14.5, glucocorticoid receptor (GR) is expressed in the heart from E10.5. To investigate whether activation of cardiac GR prior to E14.5 induces precocious fetal heart maturation, we administered dexamethasone in the drinking water of pregnant dams from E12.5 to E15.5. To test the direct effects of glucocorticoids upon the cardiovascular system we used SMGRKO mice, with Sm22-Cre-mediated disruption of GR in cardiomyocytes and vascular smooth muscle. Contrary to expectations, echocardiography showed no advancement of functional maturation of the fetal heart. Moreover, litter size was decreased 2 days following cessation of antenatal glucocorticoid exposure, irrespective of fetal genotype. The myocardial performance index and E/A wave ratio, markers of fetal heart maturation, were not significantly affected by dexamethasone treatment in either genotype. Dexamethasone treatment transiently decreased the myocardial deceleration index (MDI; a marker of diastolic function), in control fetuses at E15.5, with recovery by E17.5, 2 days after cessation of treatment. MDI was lower in SMGRKO than in control fetuses and was unaffected by dexamethasone. The transient decrease in MDI was associated with repression of cardiac GR in control fetuses following dexamethasone treatment. Measurement of glucocorticoid levels in fetal tissue and hypothalamic corticotropin-releasing hormone (Crh) mRNA levels suggest complex and differential effects of dexamethasone treatment upon the hypothalamic-pituitary-adrenal axis between genotypes. These data suggest potentially detrimental and direct effects of antenatal glucocorticoid treatment upon fetal heart function.

Platinum incorporation and differential effects of cis- and trans-diamminedichloroplatinum(II) on the growth of mouse leukemia P388/D1.

The parallel effects of cis-diamminedichloroplatinum(II) (1 microM) or trans-diamminedichloroplatinum(II) (20 microM) on the growth of mouse leukemia P388/D1 in culture, on the cellular content of protein/DNA, on the average cell volume, and on the distribution in different phases of the cell cycle were measured over a period of 70 h and compared with the amount of platinum residing in the cells. Despite different concentrations in the culture medium, similar amounts of cis- and trans-diamminedichloroplatinum(II) were incorporated. The platinum content of cells passed through an early concentration maximum in the millimolar range and decreased during prolonged times of incubation. Effects of cis-diamminedichloroplatinum(II) were marked and irreversible whereas those of trans-diamminedichloroplatinum(II) were small and transient. Proliferation was inhibited, while synthesis of protein and DNA continued almost unaffected. Cells were arrested in G2-phase of the cell cycle, and their volume increased correspondingly. The results suggested an inhibition of mitotic events, rather than of DNA replication, that caused cell arrest.

Enhanced levels of cyclic AMP, adenosine(5')tetraphospho(5')adenosine and nucleoside 5'-triphosphates in mouse leukemia P388/D1 after treatment with cis-diamminedichloroplatinum(II).

As part of the exploration of the mechanism of platinum(II) complex-induced growth inhibition and/or cytotoxicity, we studied the intracellular levels of several nucleotides during treatment of mouse leukemia P388/D1 at selected concentrations of 1 microM cis-diamminedichloroplatinum(II) (cis-DDP) and 20 microM of its trans-isomer (trans-DDP). The effects and their time-dependences are correlated with those on cell growth parameters previously published (Just G and Holler E, Cancer Res 49: 7072-7078, 1989). The effects of cis-DDP are strong and irreversible, whereas those of trans-DDP are marginal and reversible, in parallel with similar effects on cell growth parameters. Concentrations of nucleoside 5'-di- and 5'-triphosphates increase in parallel with cellular DNA and protein content by three- to four-fold after 60 hr of treatment. The nucleoside monophosphates dAMP, dGMP and dTMP reveal concentration maxima during exponential cell growth that are two- to six-fold higher than in the control cultures. Levels of cyclic AMP, adenosine(5')tetraphospho(5')adenosine (Ap4A) and CDP rise three- to five-fold above those in the control cultures within a few hours of the start of treatment. The level of coenzyme NAD+ falls below that of the control, concomitantly with an arrest of cells in the G2 phase of the cell cycle and with the appearance of giant cells. Due to the high reactivity of cis-DDP and the continuous concentration increase during the treatment, purine nucleoside 5'-triphosphates provide a possibility for the acquisition of resistance to cis-DDP. The correlation of responses of metabolically and regulatory active nucleotides with biological effects suggests their function in antitumorigenesis.

Enhancement of mass spectrometric detection of LTC4, LTD 4, and LTE 4 by derivatization.

Several acylating reagents are synthesized and used to introduce quatemary phosphonium or ammonium or ternary sulfonium functions into a simple model of a peptido leukotriene (PLT). One of these reagents was selected for further study with LTE4, LTD4, and LTC4. We demonstrate that acylation of the free amine function of PLTs to produce the 5-triphenylphosphoniumvaleryl-amide (TPPV) derivatives enhances chemical stabilities and significantly increases responses in fast-atom bombardment and continuous-flow liquid secondary ion mass spectrometry (CF-LSIMS) relative to the native PLTs. With high-performance liquid chromatography inlet to CF-LSIMS, we demonstrate the facile detection in selected ion monitoring of the TPPV derivative of 3 pg of LTD4.

Allyl group as a protecting group for internucleotide phosphate and thiophosphate linkages in oligonucleotide synthesis: facile oxidation and deprotection conditions.

[reaction: see text] The allyl group, which serves as a protecting group for an internucleotide bond for both phosphates and phosphorothioates, can be easily removed by good nucleophiles under weakly basic or neutral conditions. For a practical synthesis on solid support, camphorsulfonyloxaziridine was used as the oxidizing agent for synthesizing DNA, while the Beaucage reagent was used for preparing phosphorothioate oligomers. Both types of oligonucleotides were easily deprotected by concentrated ammonium hydroxide containing 2% mercaptoethanol.

Studies on anabolic steroids. 10. Synthesis and identification of acidic urinary metabolites of oxymetholone in a human.

Two major unconjugated acidic metabolites of oxymetholone (17 beta-hydroxy-2-hydroxymethylene-17 alpha-methyl-5 alpha-androstan-3-one, 1), namely, 17 beta-hydroxy-17 alpha-methyl-2,3-seco-5 alpha-androstane-2,3-dioic acid (2) and 3 alpha,17 beta-dihydroxy-17 alpha-methyl-5 alpha-androstane-2 beta-carboxylic acid (6a), were detected by gas chromatography/mass spectrometry in urine samples collected after oral administration of 1 to a human volunteer. Reference steroid 2 was synthesized and identified. The identification of urinary metabolite 6a was based on the synthesis of its stereoisomers and the isomerization of the methyl ester 6b to its 2-epimer, 3 alpha,17 beta-dihydroxy-17 alpha-methyl-5 alpha-androstane-2 alpha-carboxylic acid methyl ester (9b). The mechanisms accounting for the formation of these acidic metabolites are discussed.

Studies on anabolic steroids. 9. Tertiary sulfates of anabolic 17 alpha-methyl steroids: synthesis and rearrangement.

A simple and convenient method has been developed to prepare sulfates of anabolic 17 beta-hydroxy-17 alpha-methyl steroids. The sulfates of methandienone, 17 alpha-methyltestosterone, mestanolone, oxandrolone, and stanozolol were prepared. Different A-ring functions were not affected under the sulfation condition. The buffered hydrolyses of these sulfates provided the 17-epimers of the original steroids and 17,17-dimethyl-18-nor-13(14)-ene steroids, presumably via the 17-carbocations.

Visceral leishmaniasis emerging as an important opportunistic infection in HIV-infected persons living in areas nonendemic for Leishmania donovani.

BACKGROUND: Visceral leishmaniasis is an important infection in patients infected with human immunodeficiency virus and living in areas endemic for Leishmania sp. Leishmaniasis, however, is rarely suspected in patients residing in nonendemic countries. METHODS: Retrospective case analysis of 15 patients with human immunodeficiency virus infection and leishmaniasis treated at seven German clinics. The clinicopathological features and the diagnostic role of biopsy and/or cytology as compared to serology were evaluated. RESULTS: All patients were severely immunocompromised. One patient was first diagnosed at autopsy. One patient with mucocutaneous disease was diagnosed by nasal biopsy. All others had amastigotes detected in bone marrow (13/13), liver (3/3), and gastrointestinal mucosa (4/4). Serology was positive in only 6 or 13. CONCLUSION: Visceral leishmaniasis is an important opportunistic infection in patients with acquired immunodeficiency syndrome and it must be ruled out in every patient with fever and/or pancytopenia and an appropriate travel history. Because serological diagnosis is often insufficient, pathologists must be aware of the association between human immunodeficiency virus infection and leishmaniasis. Diagnosis depends on detection of the parasite in submitted specimens.

Organ donation: comparison of nurses' participation in two states.

BACKGROUND: The number of organs available for transplantation in the United States is insufficient, and the donor rate in New Jersey is particularly low. OBJECTIVES: To explore reasons nurses do or do not refer organ donors and to identify factors that contribute to differences in referral rates in New Jersey and Pennsylvania. METHODS: Registered nurses (N = 976) in 57 nongovernmental acute care hospitals, primarily in emergency departments and intensive care units, completed a questionnaire that focused on their knowledge and participation in the organ procurement process. RESULTS: Two-thirds of the subjects said they had participated in organ procurement. Pennsylvania nurses had a significantly higher involvement rate than New Jersey nurses. Pennsylvania nurses were also slightly more knowledgeable about the process. A higher proportion of nurses in both states who attended continuing education programs participated. CONCLUSIONS: Nurses need more inservice education regarding policies and procedures for organ donation.

Chimeric RNA with modified backbones: alternating methylene(methylimino) linked phosphodiester backbone oligonucleotides with 2'-OH and 2'-OMe groups.

Synthesis of a novel ribo-MMI dimer with 2'-OH and 2'-OMe in 5'- and 3'-nucleosides, respectively is presented. The synthesis was accomplished by reductive coupling of 3'-deoxy-3'-C-formyluridine and 2'-O-methyl-5'-O-methylaminouridine via a thioacetal as the key intermediate for the top part of the dimer. Incorporation of ribo-MMI dimers into oligonucleotides increased binding affinity for target RNA.

[Dynamics of radon decay product activity in saliva following therapeutic radon exposure]. / Dynamik der radonfolgeprodukt-aktivität im speichel nach therapeutischer radon-exposition.

Radon decay product activity was measured in saliva of 10 male patients 20-30 min after a 1-hour radon exposure in the gallery of the Gasteiner Heilstollen (radon activity 36.2 kBq/m(3), radon progeny activity 20.3 kBq/m(3)). In 1 patient showing relatively high activity (75th percentile) measurements were continued until 65 min after exposure. Patients were asked to collect about 2 ml of saliva in the mouth and produce it on a filter. After drying the filter at 300 degrees C, radon progeny activity was measured. Activity (median) at 20-30 min after leaving the treatment area was 4.5 Bq (25th percentile 1 Bq; 75th percentile 21 Bq). In the patient who underwent additional measurements the activity showed a further increase up to 29 Bq (35 min after radon exposure) before it continuously decreased to a very low activity (1-3 Bq) at 65 min after exposure. The results show that a significantly increased radon decay product activity is found in saliva after speleotherapeutic radon exposure. Maximum values were observed 35 min after radon exposure. Radon decay product activity almost disappeared after about 1 h.

Radon progeny activity on skin and hair after speleotherapeutic radon exposure.

The objective of present investigation was to measure radon progeny activity on hair and skin (forehead, paraumbilical, paravertebral) and its decrease after speleotherapeutic radon exposure in the gallery of the Gasteiner Heilstollen. Radon progeny activity was measured by means of a halogen-quenched Geiger-Mueller tube with a mica window (density 1.5-2.0 mg/cm2) and an effective diameter of 45 mm; beta efficiency 32% (210Bi), alpha efficiency 18% (241Am). Results are in counts per minute (cpm). All 17 patients were being treated for rheumatic disease in the galleries of the Gasteiner Heilstollen Hospital. The following activity (mean +/- standard error of the mean) was measured 25 (+/- 5) min after leaving the treatment area: on hair of the head, 1235+/-141 cpm; forehead, 503+/-78 cpm; paraumbilical 460+/-85 cpm; paravertebral, 270+/-39 cpm. Taking a shower did not significantly reduce radon progeny activity. Speleotherapeutic radon exposure causes a considerable increase in radon progeny activity on skin. The large surface of hair causes much greater activity on hair than on skin. Owing to their high adhesive properties, radon progenies are not reduced by taking a shower.

Faculty practice: nurse educators' views and proposed models.

Faculty practice is an issue that has been extensively debated, yet no consensus about its definition, purposes, or implementation has yet been achieved among nurse educators. This nationwide survey of a random sample of 909 AD and BSN educators was designed to elicit concepts of faculty practice and to find how and why faculty are implementing practice. Sixty percent of the sample are practicing nursing; the reason most frequently given was to maintain clinical skills. The 40% not practicing stated lack of time as the primary reason. Responses demonstrated no differences between AD and BSN educators regarding definition, implementation, and motivation for faculty practice. As a result of the survey, a definition of faculty practice has been formulated and conceptual models of faculty practice delineated. The models that have been developed are the Nurse-Researcher Model, Nurse-Clinician Model, and Nurse-Consultant Model.