Asymmetric amplification in catalysis by trans-1,2-diaminocyclohexane bistriflamide.

A strong asymmetric amplification is observed in the addition of diethylzinc on aromatic aldehydes in the presence of the bistriflamide of trans-1,2-diaminocyclohexane 3a. The asymmetric amplification originates from the insolubility of the catalyst precursor 3a of low enantiomeric excess (ee), with a concomitant large increase of ee for the minor soluble part of 3a. Controlled mono-N-acetylation of 3a (20% ee) at -78 degrees C allowed isolation of 4 possessing 90% ee.

Sequential transfer of day 3 embryos and blastocysts after previous IVF failures despite adequate ovarian response.

The purpose of this study was to compare IVF outcome following sequential embryo transfer (ET) with that following the transfer of early cleavage embryos among patients with previous multiple IVF failures but adequate ovarian response. A retrospective matched case-control analysis was made of the medical files of 66 women who underwent sequential transfer of day 3 embryos and blastocysts in the Chaim Sheba Medical Centre between January 1999 and May 2004. The control group included 117 matched women who underwent embryo transfer on day 3 only.

A new efficient route to chiral 1,3-disubstituted ferrocenes: application to the syntheses of (R(p))- and (S(p))-17alpha-[(3'-formylferrocenyl)ethynyl]estradiol.

Starting from (2S,4S)-2-ferrocenyl-4-(methoxymethyl)-1,3-dioxane (4), use of the stereogenic ortho-directing menthyl para-tolyl sulfoxide group, which occupies the 2' position in the ferrocenyl ring and redirects subsequent lithiation to the 3' position, allowed the synthesis of optically pure (S(p))-1-formyl-3-iodoferrocene (8), that was characterized by single-crystal X-ray diffraction. Combination of this method with a protection-deprotection strategy, using trimethylsilyl as a temporary blocking group, yielded (R(p))-1-formyl-3-iodoferrocene (13). Separate Sonogashira coupling of each of the enantiomeric iodoformylferrocenes 8 and 13 with 17alpha-ethynyl-estradiol produced (R(p))-17alpha-[(3'-formylferrocenyl)ethynyl]estradiol (14) and (S(p))-17alpha-[(3'-formylferrocenyl)ethynyl]estradiol (15), respectively.

The heart of children with steroid-resistant nephrotic syndrome: is it all podocin?

Mutations in the gene NPHS2 encoding podocin are responsible for a recessive form of steroid-resistant nephrotic syndrome (SRNS). The common phenotype is of massive proteinuria in early childhood that tends to progress to end-stage renal failure. Extrarenal manifestations have not been described.

Indomethacin tocolysis increases postnatal patent ductus arteriosus severity.

Unlabelled: Postnatally, therapeutic indomethacin administration is usually effective in mediating patent ductus arteriosus (PDA) constriction in premature infants. There are infants, however, who remain resistant to indomethacin and require more aggressive surgical intervention to facilitate ductal closure. Indomethacin tocolysis has been reported to increase the incidence of persistent PDA in premature infants.