The many faces of aggressive aortic pathology: Loeys-Dietz syndrome.

BACKGROUND: Loeys-Dietz syndrome (LDS) is a newly recognised disorder of connective tissue which shares overlapping features with Marfan syndrome (MFS) and the vascular type of Ehlers-Danlos syndrome, including aortic root dilatation and skin abnormalities. It is clinically classified into types 1 and 2. LDS type 1 can be recognised by craniofacial characteristics, e.g. hypertelorism, bifid uvula or cleft palate, whereas these are absent in LDS type 2. It is important to recognise LDS because its vascular pathology is aggressive. We describe nine LDS patients from four families, relate their features to published cases, and discuss important aspects of the diagnosis and management of LDS in order to make clinicians aware of this new syndrome. RESULTS: Characteristics found in the majority of these LDS patients were aortic root dilatation, cleft palate and/or a bifid/abnormal uvula. CONCLUSION: Because aortic dissection and rupture in LDS tend to occur at a young age or at aortic root diameters not considered at risk in MFS, and because the vascular pathology can be seen throughout the entire arterial tree, patients should be carefully followed up and aggressive surgical treatment is mandatory. Clinicians must therefore be aware of LDS as a cause of aggressive aortic pathology and that its distinguishing features can sometimes be easily recognised. (Neth Heart J 2008;16:299-304.).

[Child with swelling of eyelids and face; not always due to allergy]. / Een kind met zwelling van de oogleden en het gelaat: niet altijd allergie.

Three boys aged 3.5, 4.5 and 2.5 years, developed puffy eyelids and a swollen face. Initially, their symptoms were attributed to allergy. However, careful history taking, physical examination and laboratory studies (urinalysis and serum albumin) showed that the presenting symptoms were the first signs of nephrotic syndrome. Specific therapy induced rapid remission of the nephrotic syndrome in all patients. In children with puffy eyelids and a swollen face, nephrotic syndrome should be considered in the differential diagnosis. Appropriate laboratory studies (urinalysis) are indicated to reach the correct diagnosis so that appropriate therapy can be initiated.

Massive biatrial myxomas in a child.

Cardiac myxomas are rarely diagnosed in children, and biatrial tumors are an unusual presentation in any age group. An 8-year-old boy with massive biatrial cardiac myxomas, who presented in acute cardiogenic shock with no preceding cardiac symptomatology, is reported.

The terminal enzymes of sialic acid metabolism: acylneuraminate pyruvate-lyases.

The acylneuraminate pyruvate-lyase gene from Clostridium perfringens was sequenced and found to be most similar to the lyase gene from Haemophilus influenzae. Both the recombinant clostridial enzyme and the native enzyme from pig kidney were purified in larger amounts and characterized. The properties of the porcine lyase are similar to the microbial ones. However, the much higher degree of similarity in comparison to the microbial enzymes that was found between porcine lyase peptides and two putative mammalian lyase sequences show that the latter form an own group apart from the microbial lyases. Actual models of the acylneuraminate pyruvate-lyase reaction are discussed.

Growth of infants with neonatal growth hormone deficiency.

In view of contradictory reports on the growth hormone dependency of early postnatal growth we studied the growth curves of 15 infants with neonatal growth hormone deficiency. In seven infants the growth curve was parallel to the standards of the infancy-childhood-puberty (ICP) model (group 1), but in the remaining infants there was an immediate deviation of the growth curve (group 2). In this group the mean (SD) at 4 and 9 months of age was -3.3 (1.1) and -4.9 (1.4), respectively, when compared with the ICP model. The mean birth length in both groups was decreased and five out of 15 had a birth length of less than -2 SD. Serial measurements of the growth hormone response to provocation tests in two patients in group 2 showed decreasing concentrations, while four patients with documented complete growth hormone deficiency belonged to group 2. We conclude that growth hormone is needed for early infant growth and that the normal growth pattern in some infants with neonatal pituitary dysfunction is due to incomplete insufficiency.

Cyclic variations in the permeability of the cell wall of Saccharomyces cerevisiae.

To study cell-cycle-related variations in wall permeability of Saccharomyces cerevisiae, two approaches were used. First, an asynchronous culture was fractionated by centrifugal elutriation into subpopulations containing cells of increasing size. The subpopulations represented different stages of the cell cycle as judged by light microscopy. Cell wall porosity increased when these subpopulations became enriched with budded cells. Secondly, synchronous cultures were obtained by releasing MATa cells from alpha-factor induced G1-arrest. These cultures grew synchronously for at least two generations. The cell wall porosity increased sharply in these cultures, shortly before buds became visible and was maximal during the initial stages of bud growth. It decreased in cells which had completed nuclear migration and before abscission of the bud had occurred. The porosity reached its lowest value during abscission and in unbudded cells. We examined the incorporation of mannoproteins into the wall during the cell cycle. SDS-extractable mannoproteins were incorporated continuously. However, the incorporation of glucanase-extractable mannoproteins, which are known to affect cell wall porosity, showed cyclic oscillations and reached its maximum after nuclear migration. This coincided with a rapid decrease in cell wall porosity, indicating that glucanase-extractable mannoproteins might contribute to this decrease.