Comparative genomic hybridization (CGH) to metaphase chromosomes has been widely used for the genome-wide screening of genomic imbalances in tumor cells. Substitution of the chromosome targets by a matrix consisting of an ordered set of defined nucleic acid target sequences would greatly enhance the resolution and simplify the analysis procedure, both of which are prerequisites for a broad application of CGH as a diagnostic tool. However, hybridization of whole genomic human DNA to immobilized single-copy DNA fragments with complexities below the megabase pair level has been hampered by the low probability of specific binding because of the high probe complexity. We developed a protocol that allows CGH to chips consisting of glass slides with immobilized target DNAs arrayed in small spots. High-copy-number amplifications contained in tumor cells were rapidly scored by use of target DNAs as small as a cosmid. Low-copy-number gains and losses were identified reliably by their ratios by use of chromosome-specific DNA libraries or genomic fragments as small as 75 kb cloned in PI or PAC vectors as targets, thus greatly improving the resolution achievable by chromosomal CGH. The ratios obtained for the same chromosomal imbalance by matrix CGH and by chromosomal CGH corresponded very well. The new matrix CGH protocol provides a basis for the development of automated diagnostic procedures with biochips designed to meet clinical needs.

Morphine induced the c-fos and junB immediate early genes in neurons of the medial and ventral striatn and nucleus accumbens. Induction of c-fos and junB mRNA and Fos protein was blocked by naloxone, the D1 dopamine (DA) receptor antagonists SCH23390 and SCH39166, and the N-methyl-D-aspartate (NMDA) glutamate receptor antagonist MK801. SCH23390 attenuated morphine induction of AP-1 binding in striatum, suggesting that c-fos andjunB contribute to AP-1 binding. SCH23390 and MK801 did not block morphine induction of c-fos and junB in septum. Since the morphine induction of c-fos and junE in striatum and nucleus accumbens (NA) was similar to that observed with cocaine and amphetamine, these data support current concepts that limbic striatum and NA are among the brain regions that mediate drug abuse. Furthermore, since DA and NMDA receptors may mediate opiate reward and opiate induction of c-fos andjunE, the DA/NMDA regulation of c-fos and junB and their target genes may produce long-term changes in the striatal and NA circuits that contribute to opiate drug abuse.

No abstract

No abstract