The transcription factor CCAAT enhancer binding protein ␣ (C͞ EBP␣) is expressed at high levels in liver and adipose tissue. Cell culture studies show that C͞EBP␣ is sufficient to trigger differentiation of preadipocytes into mature adipocytes, suggesting a central role for C͞EBP␣ in the development of adipose tissue. C͞EBP␣ knockout mice die within 7-12 h after birth. Defective gluconeogenesis of the liver and subsequent hypoglycemia contribute to the early death of these animals. This short life span impairs investigation of the development of adipose tissue in these mice. To improve the survival of C͞EBP␣؊͞؊ animals, we generated a transgenic line that expresses C͞EBP␣ under the control of the albumin enhancer͞promoter. This line was bred into the knockout strain to generate animals that express C͞EBP␣ in the liver but in no other tissue. The presence of the transgene improved survival of C͞EBP␣؊͞؊ animals almost 3-fold. Transgenic C͞EBP␣؊͞؊ animals at 7 days of age show an absence of s.c., perirenal, and epididymal white fat despite excess lipid substrate in the serum, whereas brown adipose tissue is somewhat hypertrophied and shows minimal biochemical alterations. Interestingly, mammary gland fat tissue is present and exhibits normal morphology. The absence of white adipose tissue in many depots in the presence of high serum lipid levels shows that C͞EBP␣ is required for the in vivo development of this tissue. In contrast, brown adipose tissue differentiation is independent of C͞EBP␣ expression. The presence of lipid in brown adipose tissue serves as an internal nutritional control, indicating that neither nutritional intake nor lipoprotein composition is likely responsible for the absence of white fat.

SummaryIn order to investigate the relationship between the changes in glycosylation and the placental materno-fetal transport of immunoglobulin G (IgG), glycosylation profiles of IgG from healthy pregnant women and their umbilical cords at delivery were compared by use of a recently established high-performance liquid chromatography (HPLC) method. From the results of neutral oligosaccharide analysis, the digalactosyl IgG glycoform (G2) was markedly increased in pregnant women as compared with that in age-matched controls. Furthermore, the quantity of the digalactosyl glycoform in the umbilical cord was found to be higher than that in the mother. These findings demonstrate the existence of a placental selective transport with a preference for a digalactosyl oligosaccharide-linked IgG molecule. Concerning IgG sialo-oligosaccharides, however, no selective transport was observed between mother and umbilical cord. The mechanism and clinical importance of greater galactosylation in IgG still remain unclear, but we suggest that the relationship between changes in IgG galactosylation and the placental selective transport deserves further attention.Key Words: IgG galactosylation, N-linked oligosaccharides, placental transport, pregnancy, newborn Immunoglobulin G (IgG) is a major glycoprotein containing two oligosaccharides per molecule in the C-terminal half of the heavy chain dimer (Fc) region . Although over 16 kinds of neutral oligosaccharides have been shown to exist in

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Advanced high-throughput molecular cytogenetic analysis has enabled the identification of small chromosomal rearrangements, and two or more concurrently occurring chromosomal rearrangements have been identified using this technique. A girl with severe psychomotor developmental delay associated with an uncertain abnormality (detected by conventional karyotyping) in chromosome 10q had a sudden stroke at the age of 35 months. Laboratory and radiographic examinations revealed antithrombin (AT) deficiency and a patent foramen ovale (PFO). Two concurrent chromosomal aberrations, inverted duplication and deletion in the 10q26 region and a microdeletion in the 1q24.2q25.2 region including the AT gene (SERPINC1), were identified by microarray-based comparative genomic hybridization analysis. Both chromosomal aberrations were found to be of paternal origin. This study described the concurrence of chromosomal rearrangements involving two chromosomes, and estimated the frequency of two or more chromosomal aberrations as 2-4%.