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131.
The plumpness of the human newborn has long been recognized as a trait in need of explanation among researchers. Using a linear regression analysis, we find that head circumference is significantly and positively associated with BMI at birth, after gestational age and birthlength were controlled for, in a sample of 1,069 healthy liveborn routinely delivered at the University Hospital of Coimbra (partial correlation r = 0.409, P < 0.0001). This significant association is consistent with the idea that newborn fatness is related to the higher need of lipids in newborn humans as an energetic and plastic substrate during its accelerated brain growth period. As birthweight and birth head size are associated with head size and cognitive abilities in childhood and adult life, it could be postulated that these cognitive abilities could have acted as selective pressure responsible for the newborn fatness increase in our lineage. Am. J. Hum. Biol. 16:24–30, 2004. © 2003 Wiley‐Liss, Inc.  相似文献   
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Diamond's medium modified, the commercially available version of the Klaas modification of Diamond's medium, was compared to Kupferberg medium and to direct wet-mount examination for detection of trichomonads in symptomatic patients. Diamond's medium was found to be superior to both Kupferberg medium (P less than 10(-4) and wet mount (P less than 10(-6].  相似文献   
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Plasma from persons with high titers of hepatitis B antibody (anti-HBs) was used to manufacture one lot of hepatitis B "immune" globulin sufficient for four interlocking clinical trials of prevention or modification of hepatitis B infections. The trials were carried out in renal dialysis units, in medical personnel with accidental exposures to hepatitis B, in transfused patients, and in patients with fulminant hepatitis. A single policy board developed protocols that allowed comparisons among the four studies while respecting the unique requirements of each.  相似文献   
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A mutation in exon 4 of the human alpha-synuclein gene was reported recently in four families with autosomal dominant Parkinson's disease (PD). In order to examine whether mutations in this exon or elsewhere in the gene are common in familial PD, all seven exons of the alpha- synuclein gene were amplified by PCR from index cases of 30 European and American Caucasian kindreds affected with autosomal dominant PD. Each product was sequenced directly and examined for mutations in the open reading frame. No mutations were found in any of the samples examined. We conclude that the A53T change described in the alpha- synuclein gene is a rare cause of PD or may even be a rare variant. Mutations in the regulatory or intronic regions of the gene were not excluded by this study.   相似文献   
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Mutations in the PEX gene at Xp22.1 (phosphate-regulating gene with homologies to endopeptidases, on the X-chromosome), are responsible for X-linked hypophosphataemic rickets (HYP). Homology of PEX to the M13 family of Zn2+ metallopeptidases which include neprilysin (NEP) as prototype, has raised important questions regarding PEX function at the molecular level. The aim of this study was to analyse 99 HYP families for PEX gene mutations, and to correlate predicted changes in the protein structure with Zn2+ metallopeptidase gene function. Primers flanking 22 characterised exons were used to amplify DNA by PCR, and SSCP was then used to screen for mutations. Deletions, insertions, nonsense mutations, stop codons and splice mutations occurred in 83% of families screened for in all 22 exons, and 51% of a separate set of families screened in 17 PEX gene exons. Missense mutations in four regions of the gene were informative regarding function, with one mutation in the Zn2+-binding site predicted to alter substrate enzyme interaction and catalysis. Computer analysis of the remaining mutations predicted changes in secondary structure, N-glycosylation, protein phosphorylation and catalytic site molecular structure. The wide range of mutations that align with regions required for protease activity in NEP suggests that PEX also functions as a protease, and may act by processing factor(s) involved in bone mineral metabolism.   相似文献   
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