“Occult” hydrocephalus in children

The authors describe 32 children between 2 and 15 years of age who had hydrocephalus that was only clinically manifest late in life. The clinical picture of these children did not suggest an obvious increase in intracranial pressure; instead, the presenting signs were rather nonspecific and included macrocrania, mild psychomotor retardation, unsteady gait, increased muscle tone and deep tendon reflexes in the lower limbs, impaired ocular movement, epilepsy, and endocrine dysfunction. Their histories suggest the possible causes of the ventricular dilation in about one third of the cases were: perinatal hemorrhage, leptomeningitis, neurofibromatosis, and untreated aneurysm of the great vein of Galen. In 20 patients, however, no positive anamnestic findings were reported. CT scan revealed triventricular dilation in more than half of the cases; tetraventricular dilation was present in 6 patients, and biventricular dilation in the remaining subjects. All children underwent CSF shunting, which resulted in complete recovery in all but 2 cases. The most frequently recorded surgical complication was postoperative subdural effusion (7 subjects), which required surgical treatment in only 2 cases.Presented at the 15th Annual Scientific Meeting of the International Society for Pediatric Neurosurgery, New York, 1987     

Experimental Calcification of the Myocardium: Ultrastructural and Histochemical Investigations

Focal areas of calcification are frequent in rat myocardium 30 and 60 days after administration of dihydrotachysterol. These areas are PAS-positive, stain deeply with alcian blue and show high affinity for colloidal iron. Calcification is almost completely confined to intracellular structures. Small clusters of needle-shaped crystals are first found in apparently undamaged mitochondria in undamaged myocardial cells. When all the mitochondria are calcified, the cell degenerates, and inorganic crystals are laid down in relationship with its myofilaments. In other myocardial cells, clusters of amorphous or finely granular inorganic substance are found in both mitochondria and myofibrils. Both structures show signs of advanced degeneration. Inorganic substance has only occasionally been found within the structures of the sarcoplasmic reticulum. These structures do not seem to be involved in myocardial calcification under the present experimental conditions. Calcification of myocardial cells gives rise to a cellular reaction. Many macrophagic cells surround the calcified areas, which are rapidly reabsorbed. The present results show that myocardial mitochondria are actively engaged in controlling the intracellular concentration and movement of calcium ions. Their role in the myocardial contraction-relaxation cycle and the possible mechanism of myocardial calcification are discussed.     

Consensus sequence-based scheme for epidemiological typing of clinical and environmental isolates of Legionella pneumophila

A previously described sequence-based epidemiological typing method for clinical and environmental isolates of Legionella pneumophila serogroup 1 was extended by the investigation of three additional gene targets and modification of one of the previous targets. Excellent typeability, reproducibility, and epidemiological concordance were determined for isolates belonging to both serogroup 1 and the other serogroups investigated. Gene fragments were amplified from genomic DNA, and PCR amplicons were sequenced by using forward and reverse primers. Consensus sequences are entered into an online database, which allows the assignment of individual allele numbers. The resulting sequence-based type or allelic profile comprises a string of the individual allele numbers separated by commas, e.g., 1,4,3,1,1,1, in a predetermined order, i.e., flaA, pilE, asd, mip, mompS, and proA. The index of discrimination (D) obtained with these six loci was calculated following analysis of a panel of 79 unrelated clinical isolates. A D value of > 0.94 was obtained, and this value appears to be sufficient for use in the epidemiological investigation of outbreaks caused by L. pneumophila. The D value rose to 0.98 when the results of the analysis were combined with those of monoclonal antibody subgrouping. Sequence-based typing of L. pneumophila is epidemiologically concordant and discriminatory, and the data are easily transportable. This consensus method will assist in the epidemiological investigation of L. pneumophila infections, especially travel-associated cases, by which it will allow a rapid comparison of isolates obtained in more than one country.     

Sequence-Based analysis of the HLA-DRB1 polymorphism in Metalsa Berber and Chaouya Arabic-speaking groups from Morocco

To examine the genetic diversity in Morocco, the polymorphism at the HLA-DRB1 locus was investigated in two populations: the Metalsa group consisting of Berbers from north Morocco (who speak the Tarifit language and live in the Nador area), and the Chaouya group who are Arabic-speaking people from west Morocco (Atlantic coast) living in the Settat area. The DRB1 alleles of 197 healthy unrelated individuals were identified by direct DNA sequencing of exon 2 using fluorescently-labeled primers. A total of 28 and 29 alleles at DRB1 locus were identified in the Metalsa and Chaouya groups, respectively. The most frequent alleles in the Metalsa group are DRB1*03011 (20.2%), DRB1*0701 (12.12%), and DRB1*1302 (11.11%). In the Chaouya group, DRB1*0701 (16.33%), DRB1*15011 (12.76%), and DRB1*03011 (11.73%) are most common. Each population exhibits some specific variants and some uncommon alleles. The frequency of the DRB1*03011 allele differs significantly between the two populations (p = 0.0311). The DRB1 frequency distributions in the two groups suggest the effects of balancing selection. The interpopulation analysis highlighted a strong relatedness, based on genetic distances, between the two Moroccan groups and the other north Africans (the Moroccans from El Jadida area, Moroccan Souss Berbers, Algerians, and Tunisians), and to a lesser extent with the Iberians, French, and Ethiopians.     

Isokinetic knee joint test in "gonalgia sine materia"

Fifty-four subjects, aged between 20 and 35 years, divided into two subgroups, respectively 30 healthy subjects (17 males and 13 females) and 24 subjects with "gonalgia sine materia" (13 males and 11 females) underwent isokinetic exercise test in order to compare their dominant limb with the not dominant one as regard as the strength of extensor and flexor muscles of the knee. No statistically significant difference was found in any of the studied parameters in the comparison between the dominant limb and the not dominant one, both within the subgroup of healthy subjects and within the subgroup of subjects with "gonalgia sine materia". Authors conclude that psychological features may play a preeminent role in the genesis, as well as in the maintenance of "gonalgia sine materia", thus confirming previous data available in medical literature.