Three new families with arterial tortuosity syndrome

Arterial tortuosity syndrome (ATS) is a rare condition with autosomal recessive inheritance characterized by connective tissue abnormalities. The most specific clinical findings are cardiovascular anomalies including tortuosity, lengthening, aneurysm, and stenosis formation of major arteries. Also ventricular hypertrophy is frequently present. Other anomalies are skin hyperextensibility and cutis laxa, joint laxity or contractures of the joints, and inguinal herniae. Histology shows disruption of elastic fibers of the media. These features suggest that ATS is a connective tissue disorder. A biochemical or molecular defect has not yet been identified. We describe here nine additional ATS patients from three consanguineous Moroccan families and review a total of 35 patients with this uncommon condition.

Pregnancy in women with Marfan's Syndrome

Marfan's Syndrome (MFS) is an autosomal dominant condition resulting in a generalised weakness of the supporting tissues of the body. In its classical form it is associated with abnormalities of the eye, the skeletal system and the cardiovascular system. The prevalence of classical Marfan's Syndrome is 4-6 per 100,000 people. It has significant implications for affected women who are contemplating pregnancy. A multidisciplinary approach involving the specialities of maternal fetal medicine, cardiology and clinical genetics is optimal for provision of care to women with Marfan's Syndrome.

Cyclin E ablation in the mouse

E type cyclins (E1 and E2) are believed to drive cell entry into the S phase. It is widely assumed that the two E type cyclins are critically required for proliferation of all cell types. Here, we demonstrate that E type cyclins are largely dispensable for mouse development. However, endoreplication of trophoblast giant cells and megakaryocytes is severely impaired in the absence of cyclin E. Cyclin E-deficient cells proliferate actively under conditions of continuous cell cycling but are unable to reenter the cell cycle from the quiescent G(0) state. Molecular analyses revealed that cells lacking cyclin E fail to normally incorporate MCM proteins into DNA replication origins during G(0)-->S progression. We also found that cyclin E-deficient cells are relatively resistant to oncogenic transformation. These findings define a molecular function for E type cyclins in cell cycle reentry and reveal a differential requirement for cyclin E in normal versus oncogenic proliferation.

Elevated transforming growth factor β2 enhances apoptosis and contributes to abnormal outflow tract and aortic sac development in retinoic X receptor α knockout embryos

Septation of the single tubular embryonic outflow tract into two outlet segments in the heart requires the precise integration of proliferation, differentiation and apoptosis during remodeling. Lack of proper coordination between these processes would result in a variety of congenital cardiac defects such as those seen in the retinoid X receptor α knockout (Rxra–/–) mouse. Rxra–/– embryos exhibit lethality between embryonic day (E) 13.5 and 15.5 and harbor a variety of conotruncal and aortic sac defects making it an excellent system to investigate the molecular and morphogenic causes of these cardiac malformations. At E12.5, before the embryonic lethality, we found no qualitative difference between wild type and Rxra–/– proliferation (BrdU incorporation) in outflow tract cushion tissue but a significant increase in apoptosis as assessed by both TUNEL labeling in paraffin sections and caspase activity in trypsin-dispersed hearts. Additionally, E12.5 embryos demonstrated elevated levels of transforming growth factor β2 (TGFβ2) protein in multiple cell lineages in the heart. Using a whole-mouse-embryo culture system, wild-type E11.5 embryos treated with TGFβ2 protein for 24 hours displayed enhanced apoptosis in both the sinistroventralconal cushion and dextrodorsalconal cushion in a manner analogous to that observed in the Rxra–/–. TGFβ2 protein treatment also led to malformations in both the outflow tract and aortic sac. Importantly, Rxra–/– embryos that were heterozygous for a null mutation in the Tgfb2 allele exhibited a partial restoration of the elevated apoptosis and of the malformations. This was evident at both E12.5 and E13.5. The data suggests that elevated levels of TGFβ2 can (1) contribute to abnormal outflow tract morphogenesis by enhancing apoptosis in the endocardial cushions and (2) promote aortic sac malformations by interfering with the normal development of the aorticopulmonary septum.

Sex differences of body fat distribution and cardiovascular dysmetabolic factors in old age

BACKGROUND

The relationship between sexual differences of body fat distribution and cardiovascular dysmetabolic factors in old people is controversial.

OBJECTIVES

To use centrality index-derived body fat distribution to clarify its relationship with glucose tolerance status, blood pressure and lipid profile.

DESIGN

Cross-sectional survey in a tertiary-care medical centre in Tainan, Taiwan.

SUBJECTS

114 men and 101 women, aged > or = 60 years.

METHODS

We measured total % body fat and body fat distribution (reflected as centrality index) by dual energy x-ray absorptiometry, and plasma glucose, glycosylated haemoglobin, blood pressure, total cholesterol, triglyceride, high-density lipoprotein (HDL) cholesterol and atherogenic index (total cholesterol/HDL cholesterol).

RESULTS

Centrality index showed better linear correlation with cardiovascular dysmetabolic factors than body mass index, total % body fat and waist-to-hip ratio, except in systolic blood pressure. Women had higher total % body fat, but the % abdominal fat and centrality index were both higher in men. Subjects with diabetes mellitus had the highest centrality index compared with those with impaired or normal glucose tolerance. After adjustment for age and total % body fat, men still had higher diastolic blood pressure, triglyceride levels and atherogenic indices, but lower HDL cholesterol levels than women. However, when further adjusted for centrality index, the sex differences in cardiovascular dysmetabolic factors were statistically insignificant.

CONCLUSIONS

Centrality index is a useful method for assessing body fat distribution in older people. Body fat distribution is an important factor in sex differences of cardiovascular dysmetabolic factors in old people.

Congenital coronary arteriovenous fistula associated with large patent ductus

An unusual case of congenital coronary arteriovenous fistula is reported, bringing the total number of reported cases to 39.

This is the second case in which the left coronary artery system communicated directly with the right atrium, and also the second case associated with a patent ductus.

Our case is well documented by cardiac catheterization data, retrograde aortography, and postmortem findings.

Although surgical correction of both the patent ductus and coronary arteriovenous fistula was accomplished without great difficulty, the patient died 30 hours postoperatively, presumably from the effects of severe pulmonary hypertension.