Tc-99m HMPAO SPECT imaging of the central nervous system in tuberous sclerosis.

Tc-99m HMPAO was used to evaluate cerebral perfusion in a patient with tuberous sclerosis. The SPECT images demonstrated reduced HMPAO uptake in regions corresponding with MRI-confirmed locations of cortical tubers. These results indicate that the lesions are characterized by vascular perfusion deficits and support the hypothesis that cortical tubers result from developmental abnormalities of the embryonic central nervous system.

A versatile phage lambda expression vector system for cloning in Escherichia coli.

By integrating fragments from the expression plasmids pJK2 and pJK4 into a derivative of the bacteriophage lambda, we constructed the phage expression vectors lambda JK2 and lambda JK4, which allow efficient cloning of genomic or cDNA either into the 5' end or the 3' end of the lacZ gene of Escherichia coli. Expression of barrier-free DNA in phase may lead to fusion proteins consisting of active beta-galactosidase (beta Gal) plus an additional polypeptide encoded by the inserted DNA. Analysis of distinct recombinant clones is quick and easy, due to the reversible integration of the plasmid into the genome. As an example, we constructed an expression library of genomic Plasmodium falciparum DNA in lambda JK2. We polymerised (amplified) and expressed a synthetic DNA fragment, which codes for a potential antigenic determinant of the 11-1 gene of Plasmodium falciparum as a fusion to the N terminus of active beta Gal. We demonstrate that such chimeric molecules can be affinity-purified and that polypeptides can be separated from the beta Gal part by cleavage with the protease factor Xa.

The 11-1 gene of Plasmodium falciparum codes for distinct fast evolving repeats.

The 11-1 gene of Plasmodium falciparum has been investigated by DNA sequence analysis. It begins at the 5' end with a putative miniexon coding for a polypeptide which has the characteristics of a signal sequence. The miniexon is followed by a small intron. This again is followed by a large exon consisting of 9-, 18- and 27-bp repeats embedded in unique DNA. Specific antibodies isolated by affinity chromatography on a purified recombinant fusion protein expressing the three- and six-amino acid repeats were used to identify the product of the 11-1 gene. In exhibits size variations from 260 to 350 kd in different strains. Southern blot analysis with synthetic DNA as probe demonstrates that the 18-bp repeat is absent or drastically altered in two strains whereas the other repeats are present in all seven strains investigated. The unusual preference for G in the third position of some codons of the repeats but not in the unique sequences indicates rapid evolution of the repeats. Slippage during replication, unequal crossing over and selection are discussed as possible mechanisms leading rapidly to extreme diversity.

[Neurologic disorders and cerebral lesion in children with TGA (transposition of the great arteries) (author's transl)]. / Neurologische Veränderungen und cerebrale Läsionen bei Kindern mit Transposition der grossen Arterien (TGA).

118 consecutive patients with TGA were examined for neurologic disorders (ND) and cerebral lesions (CL) between 1967--1979 of whom 43 are alive. 66 had simple TGA, 52 had VSD, PS and/or coarctation as additional lesion.--43 were corrected surgically of whom 32 are alive.--Neurologic examination was performed in all, EEG, CT, arteriography, scintigraphy and autopsy when necessary or possible. Patholog. findings (CL, ND) were detected in 66; 47 had definite ND or CL, while 19 showed gross motor development delay. 52 of 118 children with TGA were without neurolog. or cerebral pathology. --Several factors were investigated for their etiologic influence: 1. Additional cardiac lesions played no significant role. 2. The lower O2 saturation in the ascending aorta of the fetal circulation in TGA may be of importance. 3. Red blood count, hemoglobin, hematocrit were higher in the group with ND or CL. 4. Early appearance of cerebral lesion should suggest earlier corrective surgery.

Straddling right atrioventricular valve in criss-cross atrioventricular relationship.

Two cases of complex congenital heart disease are described in which systemic and pulmonary bloodstreams crossed at the atrioventricular level. Both patients were examined clinically, echocardiographically, and by cardiac catheterization, including angiography, and both underwent cardiac surgery and had intraoperative mapping of their conduction systems. Both patients were found to have levocardia and situs solitus of viscera and atria, large ventricular septal defect, and straddling right atrioventricular valve. One patient had atrioventricular discordance but with the left ventricle anterior and alightly on the right and with pulmonary atresia and dextromalposition of the aorta. The other patient had atrioventricular concordance but with the left ventricle inferior and slightly on the left and with ventricular-arterial concordance to normally related great arteries and banded pulmonary trunk. To our knowledge, this combination including straddling right atrioventricular valve has not been reported in the literature before. In both patients the straddling atrioventricular valve was thought to preclude corrective operation at that time. A unique palliative procedure--left ventricle-to-pulmonary trunk shunt--was successful in the first case and partial debanding of the pulmonary trunk in the second.