Partial extracorporeal carbon dioxide removal using a standard continuous renal replacement therapy device: a preliminary study.

To test the feasibility, safety, and efficacy of partial extracorporeal CO2 removal (PECCO2R) using a standard continuous renal replacement (CRRT) device with a pediatric oxygenation membrane introduced into the circuit in a serial manner. In this retrospective single-center study, we have studied mechanically ventilated patients with persistent significant respiratory acidosis and acute renal failure requiring ongoing CRRT. Sixteen patients were treated with our PECCO2R device.

Stereodivergent synthesis of iminosugars from stannylated derivatives of (S)-vinylglycinol.

An original access to iminosugars from a cis/trans mixture of stannylated oxazolidinones 5 is reported. The dehydropiperidines 7-trans and 7-cis were obtained stereoselectively with an RS and SS configuration depending on the order of the Sn-Li transmetalation (followed by electrophilic trapping) and of the ring closing metathesis reactions due to the stereoselective epimerization of the α-aminoanion intermediate. The dehydropiperidines 7-trans and 7-cis were subsequently used for the synthesis of enantiopure homonojirimycin analogs.

Electrochemical cleavage of sulfonamides: an efficient and tunable strategy to prevent β-fragmentation and epimerization.

The electrochemical reduction of sensitive sulfonamides is described. The addition of a benzoyl group on the nitrogen atom facilitates the reductive cleavage of sulfonamides preventing β-fragmentation and epimerization. This strategy was successfully applied to the cyclopropylamine and to α-amino stannanes.

Preparation of enantiomerically enriched α-aminoorganostannanes and their applications in stereoselective synthesis.

This review deals with the preparation of chiral, nonracemic α-aminoorganostannanes and their applications in asymmetric synthesis. The pioneering works in this field date back almost 20 years ago and since then extensive research has been carried out to develop efficient and selective routes to highly enantioenriched α-aminoorganostannanes. The facile Sn/Li transmetalation of these compounds by n-BuLi has led to various applications in stereoselective synthesis.

Synthesis of highly enantioenriched chiral alpha-aminoorganotins via diastereoselective ring opening of chiral N-(arenesulfonyl) 2-tributylstannyloxazolidines.

trans-N-(Arenesulfonyl)-2-tributylstannyloxazolidines derived from (R)-phenylglycinol were diastereoselectively ring-opened by soft organometallic reagents in the presence of BF(3).OEt(2). Both higher order organocuprates and allyltributyltin afforded the desired products in good-to-excellent yields and high diastereoselectivities (dr up to 99/1).

Preparation of allyltin reagents grafted on solid support: clean and easily recyclable reagents for allylation of aldehydes.

The preparation of polymer-supported allyltin reagents was shown to be possible for both unfunctionalized and functionalized allyl units. These reagents were treated with aldehydes in the presence of cerium(III) or indium(III) salts to afford high yields of homoallylic alcohols, practically uncontaminated with organotin residues (less than 5 ppm). Some mechanism aspects are briefly discussed and the potential for regeneration and reuse of these supported reagents is pointed out.

Polymer-supported organotin reagents for regioselective halogenation of aromatic amines.

[reaction: see text] Polymer-supported triorganotin halides were used in the halogenation reaction of aromatic amines. Treatment of aromatic amines with n-butyllithium and polymer-supported organotin halides gave the corresponding polymer-bound N-triorganostannylamines, which by treatment with bromine or iodine monochloride gave the para-halogenated aromatic amines with high yields and high selectivities. The polymer-supported organotin halides reagents regenerated during the course of the halogenation reaction can be reused without loss of efficiency.

Preparation of gamma-siloxyallyltributylstannanes and their use in the synthesis of (+/-)-1-deoxy-6,8a-di-epi-castanospermine.

gamma-siloxyallyltributylstannanes were selectively obtained as E or Z isomers from beta-tributylstannylacrolein upon reaction with lithium or magnesium alkylcyanocuprates. The ability of the reagents to give a high syn selectivity when added to iminium salts has been used for the efficient synthesis of (+/-)-1-deoxy-6,8a-di-epi-castanospermine from succinimide. The key step of the synthesis was the allylstannation of the N-allyliminium intermediate followed by ring closing metathesis.

Synthesis of oligothiophene-bridged bisporphyrins and study of the linkage dependence of the electronic coupling.

A set of twelve porphyrin dimers has been prepared to give information on how the type of connectivity between a porphyrin core and a bridge can influence the interporphyrin electronic interaction. The new porphyrin systems are substituted directly at the meso position with an oligothiophene chain tethered either with a single C-C sigma bond, a trans ethylenyl group, or a acetylenyl group. The compounds are easily obtained by palladium-catalyzed cross-coupling reactions (Stille, Heck, and Sonogashira) between 5-iodo-10,15,20-(3,5-ditert-butylphenyl)porphyrin and the appropriate oligothiophene derivative.

Hemodynamic and echocardiographic effects of hemofiltration performed during cardiopulmonary bypass.

Objective: To evaluate the effects of hemofiltration performed during rewarming before emergence from cardiopulmonary bypass on hemodynamic and echocardiographic parameters.

Design: Prospective randomized study; blind analysis of echocardiographic parameters and hemodynamic parameters.

Setting: Single-center study performed in a university hospital.

An efficient synthetic approach to highly conjugated porphyrin-based assemblies containing a bipyridine moiety.

[structure: see text] An efficient and potential stepwise strategy involving the mixed sequence of Stille and Wittig-Horner reactions was used for the preparation of a polyene-substituted bis-porphyrin incorporating a bipyridine moiety.

Syntheses of Theaspirone and Vitispirane via Palladium(II)-Catalyzed Oxaspirocyclization.

Total syntheses of theaspirone (A and B) and vitispirane (A and B) are described. The key step in the syntheses is the palladium(II)-catalyzed intramolecular oxaspirocyclization of diene alcohol 4 to either vitispirane or the allylic alcohol 9. The outcome of the oxaspirocyclization is very much dependent on the solvent employed.

Ligation of the patent ductus arteriosus in premature infants--indications and procedures.

Premature newborns with patent ductus arteriosus can be managed by prostaglandin inhibition, but this medical treatment carries a high risk of renal failure, and other complications such as necrotizing enterocolitis and hematologic disorders have been described. Echocardiography gives an early confirmation of shunt and surgical treatment may be proposed. The aortic arch anatomy in the premature infant may not be as simple to determine as the anatomy of an older child.

[Peripubertal longitudinal study by echocardiography of left heart development in a group of ice hockey players].

The modalities of left ventricular (LV) adaptation (dilatation and/or hypertrophy) to exercise are not as well known in children as in adults. Therefore, the authors followed up 11 national ice hockey players, initially aged 10, following an eight hour per week training schedule for a period of 5 years. M mode echocardiographic studies were carried out each year during the training period to measure LV internal dimensions, wall thickness, myocardial mass and contractility (fractional shortening and systolic stress index).

[Development of a safe technique for central venous access in pediatrics. Our experience with 700 percutaneous central catheters].

Since 1977, the authors have performed 708 percutaneous catheterizations of superior vena cava in pediatric patients (from premature infant of 15 year old children). The greater part of these catheterizations concerns the internal jugular vein. Subclavian catheterization was rapidly abandoned because it is judged too dangerous in children.

[Vascular injuries during percutaneous catheterization of the lower neck in children].

Four cases of vascular injuries of subclavian artery in children are reported after 414 percutaneous catheterization between 1980 and 1986. The first case reported is a 2 month old child with a right subclavian aneurysm after punction, witch be treated by a successful resection-anastomosis. Three others children, 12, 13, and 14 years old have been catheterized by a jugular approach for one and by a subclavian approach in the others.

[Gardner syndrome treated by total colectomy with preservation of the internal sphincter. Apropos of 3 cases].

Familial polyposis and more particularly Gardner's syndrome is a difficult affection to treat in children, due to the risk of degeneration of polyps. Two factors are accepted by all authors as being of major importance: the need for early treatment to avoid degeneration; the advantage of maximum mucosal excision to avoid repeated follow up examinations and removal of further polyps from the remaining rectum. Three cases of familial polyposis and Gardner's syndrome were treated by either total colectomy and rectal mucosectomy (2 cases) or a partial Reifferscheid procedure (1 case).