Characterization and differentiation of ruthenium(II) complexes with 1,4,7-trithiacyclononane and nitrogen heterocycles by electrospray mass spectrometry

Electrospray ionization mass spectrometry (ESIMS) was used to characterize a series of new ruthenium(II) complexes with several nitrogen heterocycles and a common ligand: the crown thioether 1,4,7-trithiacyclononane, [9]aneS(3). ESIMS allows the easy identification of the [Ru(II)Cl([9]aneS(3))Y]X complexes, where Y is a bidentate nitrogen heterocycle and X is Cl(-) or PF(6)(-), through the formation of two diagnostic ions by fragmentation of the common ligand [9]aneS(3). Structures for these ions and mechanisms for their gas-phase formation are proposed based on data from product ion spectra.

Dimethyl ether chemical ionization of arylalkylamines

The gas-phase reactions of dimethyl ether (DME) ions with a number of biologically active arylalkylamines of the general formula R(1)R(2)C(6)H(3)CHR(3)(CH(2))(n)NR(4)R(5), where R(1) = H or OH, R(2) = H, F, NO(2), OH or OCH(3), R(3) = H or OH, R(4) and R(5) = H or CH(3), have been studied by means of chemical ionization mass spectrometry. Under the experimental conditions used, the most abundant DME ion is the methoxymethyl cation (CH(3)OCH(2)(+), m/z 45). The unimolecular metastable decompositions of the [M + 45](+), [M + 13](+) and [M + 15](+) adducts formed have been interpreted in terms of the initial site of reaction with the amines and the presence of different functional groups in the molecule. This has permitted establishment of general fragmentation patterns for the adducts, and their correlation with structural features of the molecules. The main site of reaction of the ion CH(3)OCH(2)(+) with the amines seems to be the amino group, particularly if the amine is primary, although a competition with attack on the aromatic ring and especially on the benzylic hydroxy group is observed. In a few cases the reaction mechanisms have been elucidated through the use of deuterated amines obtained by H/D exchange with D(2)O.

Gas-phase deprotonation of arylalkylamines. A collision-induced dissociation study

The collision-induced dissociation (CID) of deprotonated arylalkylamines of general formula R(1)C(6)H(4)CHR(2)CH(2)NR(3)(2) (where R(1) = H, OH, F or NO(2); R(2) = H or OH; R(3) = H or CH(3)) generated by negative chemical ionization with H(2)O and D(2)O as ionizing reagents, is discussed. The negative chemical ionization mass spectra show that, in the absence of a hydroxy group in the aromatic ring, deprotonation takes place at the benzylic position whereas the proton is lost from the OH group when present. The nitro compound forms only M(-.) ions. The CID spectra of the deprotonated molecules show that fragmentations are strongly dependent on the structural features of the molecules, namely the presence or absence of substituents in the aromatic ring or aliphatic chain. Copyright 1999 John Wiley & Sons, Ltd.

Schimke immuno-osseous dysplasia: case report and review of 25 patients

Immuno-osseous dysplasia is characterised by spondyloepiphyseal dysplasia, lymphopenia with defective cellular immunity, and progressive renal disease. We describe a patient with a severe form of the disease, review the features of another 24 patients, and discuss the previous classification. The differences between the two groups are not striking, and although similarities are greater between affected sibs, the same diagnosis of Schimke immuno-osseous dysplasia should apply to them all. The aetiology and physiopathology of this rare osteochondrodysplasia of presumed autosomal recessive inheritance remain unknown.

Argon plasma coagulation therapy for hemorrhagic radiation proctosigmoiditis

BACKGROUND

Radiation-induced proctosigmoiditis is a serious complication of pelvic radiation therapy. Rectal bleeding occurs among 6% to 8% of these patients and is extremely difficult to manage. Pharmacotherapy is generally ineffective, whereas surgical treatment is associated with high morbidity and mortality. Argon plasma coagulation is a new method of noncontact electrocoagulation well suited for hemostasis of large bleeding areas.

METHODS

From December 1996 through March 1998, we used argon plasma coagulation to treat 28 patients with hemorrhagic radiation-induced proctosigmoiditis. Indications for treatment were anemia (n = 18) and persistent bleeding despite pharmacotherapy (n = 10). Argon flow and electrical power were set at 1.5 L/min and 50 W. The severity of rectal bleeding was graded from 0 to 4 (highest), and hemoglobin levels were recorded before and after treatment.

RESULTS

Eighty-two therapeutic sessions were performed (median 2.9 sessions per patient). The severity score for rectal bleeding dropped at least 1 point for all but 2 patients, and the mean value decreased from 2.96 to 0.68. Average hemoglobin level increased 1.2 gm/dL (1.9 gm/dL among anemic patients). No serious complications were observed.

CONCLUSIONS

Argon plasma coagulation appears to be a simple, safe, and effective technique in the management of hemorrhagic radiation-induced proctosigmoiditis.

Anti-glomerular basement membrane nephritis in a 5-year-old girl

We report a 5-year-old girl with anti-glomerular basement membrane nephritis. Her outcome was excellent with clearance of antibody and recovery of renal function 5 weeks after the start of immunosuppression and plasmaphaeresis.

d-Amphetamine interaction with glutathione in freshly isolated rat hepatocytes

Hepatocellular damage has been reported as a consequence of amphetamine intake for which little is known about the respective biological mechanisms involved. To give a better insight of cellular d-amphetamine effects, the present study was performed to evaluate d-amphetamine effects on glutathione homeostasis, in vitro, using freshly isolated rat hepatocytes. Cell viability and lipid peroxidation were also evaluated. Incubation of freshly isolated rat hepatocytes with d-amphetamine (0.08, 0.20, 0.40, and 2.00 mM) induced a concentration dependent glutathione depletion which was observed at all times (1, 2, and 3 h of incubation). After 3 h of incubation, cellular GSH decreased to 85%, 78%, 71% and 47% of control levels for the referred concentrations, respectively. At the third hour of incubation, GSSG levels were only slightly increased for the three higher concentrations of d-amphetamine. The mass spectral study of the methanolic supernatants obtained from hepatocytes incubated with all d-amphetamine concentrations revealed the presence of the p-hydroxyamphetamine glutathione adduct (glutathion-S-yl)-p-hydroxyamphetamine. Pretreatment of hepatocytes with the P450 inhibitors metyrapone (1 mM) and iprindole (10 microM) significantly prevented the glutathione depletion induced by d-amphetamine. This inhibition was more effective for iprindole than for metyrapone. Incubation of isolated hepatocytes with p-hydroxyamphetamine (0.10 mM) for 3 h did not result in any modification of cell viability or GSH or GSSG levels. Also, in the mass spectrum study performed on these samples, the characteristic adduct obtained for d-amphetamine incubations was not detected. The above data suggest that the observed glutathione depletion induced by d-amphetamine is at least in part due to the conversion of d-amphetamine into (glutathion-S-yl)-p-hydroxyamphetamine and that P450 2D seems to have an important role in this metabolism. In spite of the results obtained, showing glutathione homeostasis alterations, incubation of freshly isolated rat hepatocytes with d-amphetamine did not result in any modification of cell viability or lipid redox status.

13C solid-state nuclear magnetic resonance and Fourier transform infrared studies of the thermal decomposition of cork

The thermal decomposition of cork has been studied by Fourier transform infrared (FTIR) spectroscopy and 13C solid-state nuclear magnetic resonance (NMR) spectroscopy with cross-polarization and magic-angle spinning (CP-MAS), high-power 1H decoupling (HPDEC) and cross-polarization depolarization-polarization (CPDP). Waxes and other soluble components of cork begin to decompose at ca. 150 degrees C. This is accompanied by partial decomposition of suberin, probably initiated at the points of attachment to the cell wall. The carbohydrates begin to decompose at ca. 200 degrees C. The decomposition of lignin begins at 250-300 degrees C, while suberin undergoes further degradation. Significant amounts of coke are formed in the process. At 400 degrees C cork has been transformed into coke with traces of partially decomposed suberin. The thermal decomposition of cork is dependent on the calcination time, particularly in the 200-350 degrees C range.

[Evolution of acute transitory renal insufficiency in severe hypernatremic dehydration]

In this study the authors analysed the evolution of blood urea nitrogen in 14 infants during treatment of hypernatremic dehydration. BUN values decreased at a low rate comparing with usual standard limits: a) a correlation between initial BUN and natremia was observed, b) in 9 out of 14 infants there was a transient elevation of BUN, between 5 to 24 hours after the beginning of rehydration, and c) renal function was normal in 8 children who were reevaluated 3 to 28 months after the episode of dehydration.