Perinatal lethality of microtubule-associated protein 1B-deficient mice expressing alternative isoforms of the protein at low levels.

Microtubule-associated protein 1B (MAP1B) has been implicated in axogenesis in cultured cells. To gain insight into the functions that MAP1B plays in vivo, we analyzed a strain of Map1B mutant mice generated by a gene trapping approach. Homozygous mice die on the first day after birth, probably due to a severe abnormal development of the nervous system. They present alterations in the structure of several brain regions. The normal Map1B gene yields different protein isoforms from alternatively spliced transcripts. The smaller isoforms were present in wild type, hetero-, and homozygous mice, but their expression was higher in the mutants than in the wild-type. Moreover, trace amounts of MAP1B protein were also observed in Map1B homozygous mutants, indicating an alternative splicing around the gene trap insertion. Thus, the Map1B gene trapped mutation reported in this work did not generated a null mutant, but a mouse with a drastic deficiency in MAP1B expression. Analyses of these mice indicate the presence of several neural defects and suggest the participation of MAP1B in neuronal migration.

Visual loss as the presenting sign of Jeune syndrome.

We describe a 5-year-old girl with Jeune syndrome. The presenting symptoms included visual loss and night blindness only. In the neonatal period she had surgery on both hands for bilateral polydactyly. Following clinical and radiological examination a diagnosis of Jeune syndrome was proposed. Although Jeune syndrome is often characterized by multiple organ abnormalities, our patient presented with ocular symptoms at the age of 5 years.

Prenatal indomethacin toxicity in one member of monozygous twins; a case report.

A mother, treated with indomethacin because of premature labour, delivered a pair of monozygous twins at a gestational age of 33 weeks. Because of foetal transfusion syndrome, the first twin was polycythaemic and the second anaemic. The latter was also hydropic, suffered from anuria requiring peritoneal dialysis, and showed signs of severe pulmonary hypertension, probably as a consequence of intra-uterine constriction of the ductus arteriosus. The possible interaction between foetal transfusion syndrome, anuria, premature constriction of the ductus arteriosus and the prenatal administration of indomethacin is discussed. In general, indomethacin should cautiously be used as a tocolytic agent.

Single photon emission computed tomography (SPECT) in seizure disorders in childhood.

In 38 children with partial seizures, the EEG, CT and NMR findings were compared to the results obtained with Tc99m HMPAO single photon emission computed tomography (SPECT) in order to determine whether SPECT is a useful adjunct to EEG, CT and NMR in this age group. In 3 out of 7 patients with a normal EEG, SPECT showed focal abnormalities. Nine patients whose EEGs did not show adequate lateralization had an abnormal SPECT which revealed a focus. In 14 out of 21 patients with a normal CT, SPECT showed focal changes in 13 patients and diffuse changes in the other one. In 7 out of 12 patients with a normal NMR, SPECT showed focal abnormalities. Although clinical history and a careful description of the seizures are the most valuable information in partial seizure disorders, SPECT imagining gives valuable additional information, which might target treatment. SPECT was superior to CT and NMR with respect to the depiction of some kind of abnormality.