Genotype at a major locus with large effects on apolipoprotein B levels predicts familial combined hyperlipidemia

A sample enriched for familial combined hyperlipidemia (FCHL) was examined for evidence of an association between genotype at an apolipoprotein B (apoB) elevating locus defined by complex segregation analysis and FCHL. Complex segregation analysis detected a locus with a large effect on plasma apoB levels and was used to compute the most probable genotype of family members. None of the 35 normolipidemic adults carried a copy of the allele associated with elevated apoB levels, yet 58% of the 109 adults with FCHL carried 1 (29%) or 2 (28%) copies. Two of 28 (7%) normal children had 1 copy of this allele and none had 2 copies, while 88 of 182 (48%) children with FCHL had 1 (26%) or 2 (22%) copies. Further, 4l of 48 (85%) individuals classified as having hyperapobetalipoproteinemia did not carry a copy of this “elevated apoB” allele. Therefore, the presence of the allele associated with elevation of apoB level is highly predictive of FCHL and this association cannot be explained solely by the presence of elevated apoB levels in FCHL, suggesting that the locus controlling apoB levels may play an etiologic role in FCHL. © 1993 Wiley-Liss, Inc.     

Genetic components and intellectual functioning during senescence: A 20-year study of aging twins

Psychological test scores of 13 identical and six fraternal pairs of twins aged 77–88 years were analyzed. These individuals are the survivors of a group of senescent twins studied earlier. The identical twins remained more similar than the fraternal ones, and there was a remarkable conservation of cognitive abilities in most individuals. Moreover, preservation of intelligence and longevity may be related.     

MR nerve imaging of the wrist and hand

Peripheral nerve imaging is still in a relatively early phase of development. This article explains a few of the important technical aspects of peripheral nerve imaging and reviews the results of animal experiments that form the foundation for interpreting image results. The clinical discussion focuses on the use of MR imaging for patients with carpal tunnel syndrome, keeping in mind that many aspects of the imaging technique may be applied to other areas. The reliability, diagnostic accuracy, and potential indications for peripheral nerve imaging are discussed.     

Cigarette desirability and nicotine preference in smokers

We conducted two experiments to explore the role of nicotine in the maintenance of cigarette smoking behavior. In Experiment 1 we determined that, compared to 0 or 2 mg injections, an injection of 4 mg nicotine base into the filter of non-nicotine cigarettes significantly increased their desirability. In Experiment 2, to determine how nicotine-seeking varied across a wide range of cigarette deprivation, we studied nicotine preference under three cigarette deprivation conditions: overnight abstinence, 30 min deprivation, and immediately after smoking (satiation condition). Nicotine preference was assessed by allowing subjects to freely adjust the nicotine concentration of each puff using a smoke mixing device. Nicotine preference was greatest after overnight deprivation. Least after satiation, and intermediate after 30 min deprivation. However, nicotine seeking increased as a function of cigarette deprivation despite the fact that higher nicotine puffs were rated as harsher, stronger and less desirable than lower nicotine puffs. The results of both experiments suggest an inverted-U relationship between nicotine content and desirability.     

Zementaugmentation bei osteoporotischen Wirbelkompressionsfrakturen

High-quality evidence has raised significant questions on the widespread use of vertebroplasty in the treatment of osteopenic vertebral insufficiency fractures. Further research is shifting the burden of proof on procedures such as balloon kyphoplasty and other interventions. New prospective clinical trials may need to consider including sham arms to enhance their relevance.