Drug polyconsumption is associated with increased synchronization of brain electrical-activity at rest and in a counting task.

Drug abusers typically consume not just one but several types of drugs, starting from alcohol and marijuana consumption, and then dramatically lapsing into addiction to harder drugs, such as cocaine, heroin, or amphetamine. The brain of drug abusers presents various structural and neurophysiological abnormalities, some of which may predate drug consumption onset. However, how these changes translate into modifications in functional brain connectivity is still poorly understood. To characterize functional connectivity patterns, we recorded Electroencephalogram (EEG) activity from 21 detoxified drug abusers and 20 age-matched control subjects performing a simple counting task and at rest activity. To evaluate the cortical brain connectivity network we applied the Synchronization Likelihood algorithm. The results showed that drug abusers had higher synchronization levels at low frequencies, mainly in the θ band (4-8 Hz) between frontal and posterior cortical regions. During the counting task, patients showed increased synchronization in the ß (14-35 Hz), and γ (35-45 Hz) frequency bands, in fronto-posterior and interhemispheric temporal regions. Taken together 'slow-down' at rest and task-related 'over-exertion' could indicate that the brain of drug abusers is suffering from a premature form of ageing. Future studies will clarify whether this condition can be reversed following prolonged periods of abstinence.

Trisomy 12 mosaicism confirmed in multiple organs from a liveborn child.

This patient, in whom trisomy 12 mosaicism was confirmed in multiple organs, is the fifth case diagnosed postnatally and the first reported for whom a meiotic origin of the trisomy, maternal meiosis I, was determined. Mosaic aneuploidy was suspected because of pigmentary dysplasia, a frequent but non-specific finding in chromosomal mosaicism. The severe phenotype of this child, who died in infancy with a complex heart malformation, was probably a result of the high percentage of trisomic cells. Cytogenetic and interphase fluorescent in situ hybridization analyses showed a highly variable distribution of aneuploid cells in the nine tissues studied, from none in blood and ovary to 100% in spleen and liver. The trisomy arose meiotically with apparent post-zygotic loss of one of the chromosomes 12; uniparental disomy for this chromosome in the diploid cell line was excluded. The phenotype of the cases reported in living or liveborn individuals has been extremely variable, ranging from the present case, in which the child died in infancy with multiple malformations and pigmentary dysplasia, to a fortuitous finding in an adult studied for infertility. The variation in severity is probably determined by the proportion and distribution of the trisomic cells, which is linked to the timing of the non-disjunctional error.

Probable post-synaptic alpha 2 adrenergic mediated effect of xylazine on goat uterine motility.

Xylazine has been characterized as a selective alpha 2-adrenoceptor agonist, which has explained its central nervous system depressant and other pharmacological effects. In order to characterize the effect of xylazine on uterine motility during the oestrus cycle in goats, intrauterine pressure changes were recorded in cycling goats using balloon-tipped catheters placed in the uterine horns and connected to pressure transducers and a recorder. The effect of xylazine on myometrial activity was studied by giving increasing doses of the drug (1.0, 10.0, 100.0 or 500.0 micrograms/kg) intravenously (i.v.) to animals either in the follicular or the luteal phase of the cycle. To establish the subtype of alpha adrenergic receptor mediating the action of xylazine, goats were pretreated with either prazosin (1.0 mg/kg, i.v.) or yohimbine (1.0 micrograms/kg, i.v.). To establish whether the effect of xylazine was pre- or post-synaptic, xylazine (100 mg/kg, i.v.) was administered to goats pretreated with reserpine (0.8 mg/kg, i.p.) to deplete presynaptic catecholamine stores. Xylazine induced a significant and dose-dependent increase on uterine motility in cycling goats, apparently mediated by post-synaptic alpha 2-adrenoceptors.

[Myocardial revascularization with the gastroepiploic artery. The initial experience]. / Revascularización miocárdica con arteria gastroepiploica. Experiencia inicial.

The internal mammary artery is widely recognized as the graft of choice for coronary artery bypass grafting at present. Alternative conduits have been investigated in order to find other adequate long-term grafts. The right gastroepiploic artery has been recently used as a graft to bypass distal coronary vessels. From November 1989 to April 1990 we have implanted this artery in 33 cases (32 in situ and one free grafts). The pedicled grafts were implanted in 17 patients in the main right coronary artery, in 13 we grafted the right distal branches, in one the left anterior descending, and the circumflex branch in one. The free graft was implanted in the first diagonal. Mean grafts per patient was of three in this series, with a mean of 2 arterial grafts per patient. One patient died in the early postoperative period. The remaining patients had an uncomplicated postoperative period. Thirteen patients underwent graft and coronary angiography. Direct or indirect graft patency was confirmed in all cases. The final important issue concerning the long-term patency of this graft will be solved in the future, but short-term patency rates of the right gastroepiploic artery can be anticipated when proper techniques are used.