Physical activity modulates the effect of a lipoprotein lipase mutation (D9N) on plasma lipids and lipoproteins

We investigated interactions between a mutation (D9N) in the lipoprotein lipase (LPL) gene and physical activity, as well as other lifestyle factors, on lipid traits in a population-based sample of Dutch men and women (n = 379). We used questionnaire information to classify physical activity, alcohol consumption, and smoking habits, while overweight was defined as a body mass index (BMI) > 25 kg/m2. Non-fasting blood samples were used for the determination of lipid traits and the D9N genotype. Fifteen subjects (4%) carried the mutation. They presented with higher levels of total cholesterol, apolipoprotein (apo) B and triglycerides compared to non-carriers. While no interactions with overweight, alcohol consumption, and smoking were found, a strong interaction between the D9N mutation and physical activity became apparent. Physically inactive D9N carriers (n = 5) had considerably higher total cholesterol (+2 mmol/l, p < or = 0.0001) and apo B levels (+63 mg/dl, p < or = 0.0001) compared to non-carriers of this mutation, whereas their high-density lipoprotein (HDL)-cholesterol concentrations were lower (-0.22 mmol/l, p < 0.05). This was not the case for physically active D9N carriers (n = 10). In conclusion, a common variant of the LPL gene (D9N) adversely affects plasma lipid and lipoprotein profiles. However, the unfavorable consequences may be counteracted by physical activity.     

Detection of genomic deletions of PKP2 in arrhythmogenic right ventricular cardiomyopathy

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited myocardial disease that predominantly affects the right ventricle and is associated with ventricular arrhythmias that may lead to sudden cardiac death. Mutations within at least seven separate genes have been identified to cause ARVC, however a genetic culprit remains elusive in approximately 50% of cases. Although negative genetic testing may be secondary to pathogenic mutations within undiscovered genes, an alternative explanation may be the presence of large deletions or duplications involving known genes. These large copy number variants may not be detected with standard clinical genetic testing which is presently limited to direct DNA sequencing. We describe two cases of ARVC possessing large deletions involving plakophilin‐2 (PKP2) identified with microarray analysis and/or multiplex ligation‐dependent probe amplification (MLPA) that would have been classified as genotype negative with standard clinical genetic testing. A deletion of the entire coding region of PKP2 excluding exon 1 was identified in patient 1 and his son. In patient 2, MLPA analysis of PKP2 revealed deletion of the entire gene with subsequent microarray analysis demonstrating a de novo 7.9 Mb deletion of chromosome 12p12.1p11.1. These findings support screening for large copy number variants in clinically suspected ARVC cases without clear disease causing mutations following initial sequencing analysis.     

Effects of prenatal cocaine exposure and postnatal environment on child development

Studies on the long-term developmental effects of in utero cocaine exposure are few and the small number of studies published do not consider the postnatal environment. The present investigation was conducted to quantify the role that postnatal environment played compared to prenatal exposure. Four groups of 25 infants, each assessed at 12 months of age, were included in the study design: 1) noncocaine-exposed children residing with their biological parents in low socioeconomic environments, 2) cocaine-exposed children living with their biological parents in low socioeconomic environments, 3) noncocaine-exposed children adopted at birth in middle to upper-middle socioeconomic environments, and 4) cocaine-exposed children adopted at birth. Infants were assessed by the Uzgiris-Hunt Ordinal Scales of Infant Psychological Development, the Fagan Test of Infant Intelligence, and the Infant Monitoring Questionnaire. Height and head circumference were measured. Gender and ethnicity were controlled statistically. Significant differences were found in cognitive functioning, in fine motor development, and in physical growth between control and prenatally cocaine-exposed children. Adoption enhanced cognitive functioning and fine motor skills among infants not exposed to cocaine prenatally, but had no apparent effect on infants prenatally exposed to cocaine. Am. J. Hum. Biol. 12:417–428, 2000. © 2000 Wiley-Liss, Inc.     

Central pontine myelinolysis and its imitators: MR findings

The clinical, radiologic, and neuropathologic findings in 13 patients with central pontine myelinolysis were reviewed. Antemortem computed tomography (CT) had been performed in nine, and ante- or postmortem magnetic resonance (MR) imaging in 11. Chronic alcoholism or rapid correction of hyponatremia was present in over 75% of cases. One CT scan was positive, but only on retrospective review. In all but one patient, MR imaging eventually revealed an abnormality within the pons; in two patients the initial study was normal. The lesions varied in shape, with peripheral involvement in two patients and extrapontine involvement in four. The abnormality was smaller at 6-month follow-up in one patient and unchanged at 1 year in another. One patient never had a demonstrable pontine lesion but did have symmetric basal ganglia abnormalities, which were consistent with extrapontine myelinolysis. MR imaging disclosed similar central pontine alterations resulting from infarct, metastasis, glioma, multiple sclerosis, encephalitis, and radiation or chemotherapy; thus, such changes are not unique.     

Clinical MR imaging with a Helmholtz-type surface coil

Limited-field-of-view radio-frequency receiver antennas provide improved near-field sensitivity for magnetic resonance imaging by decreasing the antenna volume. The Helmholtz-type surface coil, consisting of two flat rings, is an organ-encompassing antenna that takes advantage of this principle to yield an improved signal-to-noise ratio (S/N). The coil was tested in a group of 50 patients and 16 healthy volunteers. Images obtained with the Helmholtz coil demonstrated quantitatively superior S/N of 2.2-fold or greater than that of comparison body coil images, as well as qualitatively superior anatomic resolution.     

US-guided percutaneous biopsy: use of a screw biopsy stylet to aid needle detection

Insertion of a screw biopsy stylet into a thin-walled biopsy needle greatly enhances detection of the needle during ultrasound-guided percutaneous biopsy. This technique is helpful when precise needle-tip localization is needed for biopsies of small lesions.