Prevalence of human cytomegalovirus congenital infection in Portuguese newborns.

Human cytomegalovirus (HCMV) is considered the most frequent cause of congenital infection, occurring in 0.2 to 2.2% of all live births. Since this is a wide range of prevalences observed in different studies, it would be desirable to investigate the prevalence of this infection at national level. The aim of this study was the evaluation of the national prevalence of HCMV congenital infection. We analysed a total of 3,600 Guthrie cards collected from Portuguese newborns during a period of 14 months (August 2003 to September 2004). The cards covered all regions of Portugal and were proportional to the number of births in each region. A heat DNA extraction method was used, followed by DNA amplification by nested PCR. Sensitivity and specificity of this method were evaluated as 93% and 100%, respectively, using 28 cards from HCMV-positive and 280 cards from HCMV-negative children. The national prevalence of congenital HCMV was determined as 1.05% (95% confidence interval: 0.748-1.446). This is the first study of the prevalence of HCMV congenital infection at national level in Portugal. It suggests that Portugal may have one of the highest prevalences of congenital HCMV infection in Europe.

Original Article: Changes in Platelet Function, von Willebrand Factor and Factor VIII in Patients Undergoing Aorto-bifemoral By-pass with Dacron Grafts.

Platelets play a major role in the development of patency complications in vascular grafts. The aim of this study was to evaluate changes in platelet count and function, and also in factor VIII:C (FVIII:C) and von Willebrand factor (vWF) plasma levels, induced by aorto-bifemoral by-pass with Dacron grafts in seven patients. Platelet count, platelet aggregate ratio (PAR), and platelet aggregability induced by several stimuli, as well as FVIII:C and vWF plasma levels were evaluated before and on days 1,4,9 and 11 after surgery. We observed a mild thrombocytopenia on day 1, followed by a progressive increase in platelet count, which attained a relative thrombocytosis on the 11th day. PAR did not vary significantly during the whole observation period. Platelet aggregation, assayed by the optical method using ADP, epinephrine, arachidonic acid, collagen and ristocetin, (decreased on days 1 and 4). Thereafter, an increase in aggregation was observed until day 11 when hyperaggregability was verified. FVIII:C and vWF peaked on the 4th day, decreasing progressively to pre-surgery values on day 11.

A 3-base pair in-frame deletion of the phenylalanine hydroxylase gene results in a kinetic variant of phenylketonuria.

Phenylketonuria (PKU) is an autosomal recessive disease due to deficiency of a hepatic enzyme, phenylalanine hydroxylase (PAH). The absence of PAH activity results in typical PKU while persistence of a residual enzyme activity gives rise to variant forms of the disease. We report here a 3-base pair in-frame deletion of the PAH gene (delta 194) in a mild variant, with markedly reduced affinity of the enzyme for phenylalanine (Km = 160 nM), and we provide functional evidence for responsibility of the deletion in the mutant phenotype. Since the deletion was located in the third exon of the gene, which presents no homology with other hydroxylases, we suggest that exon 3 is involved in the specificity of the enzyme for phenylalanine. Finally, since none of the 98 PKU patients tested were found to carry this particular deletion, our study suggests that this molecular event probably occurred recently on the background of a haplotype 2 gene in Portugal.