Search PubMed⌕ Search

Biomedical subjects

M Sanak

Publications and source records attributed to M Sanak.

47 records · Page 3Linked to original sources
PubMed1995

Fine deletion mapping of the p22 region of the human X chromosome using a radiation-induced hybrid panel.

Radiation-induced somatic cell hybrids containing fragments of the human X chromosome were constructed. A panel of 17 hybrids was selected with the help of known markers in the Xp22 region. These hybrids identified 11 different breakpoints between Xp22.2 and Xp21.3. Eight markers were located in eight of the nine corresponding intervals, resulting in the following physical map: tel...DXS89-DXS278-DXS85-(DXS1224, DXS16)-(GLRA2, DXS987)-DXS207-(DXS-197, DXS1053)-(DXS43, DXS1195)-(DXS1229, DXS-999)-(DXS1052, DXS92, DXS274)-(DXS41, DXS1226)-DXS1198-DXS28...cen.

Animals↗
PubMed1994

A gene for achondroplasia-hypochondroplasia maps to chromosome 4p.

Achondroplasia (ACH) is a frequent condition of unknown origin characterized by short-limbed dwarfism and macrocephaly. Milder forms, termed hypochondroplasias (HCH) result in short stature with radiological features similar to those observed in ACH. We report on the mapping of a gene causing ACH/HCH to human chromosome 4p16.3, by linkage to the iduronidase A (IDUA) locus, in 15 informative families (Z max = 3.01 at theta = 0 for ACH; Z max = 4.71 at theta = 0 for ACH/HCH). Multipoint linkage analysis provides evidence for mapping the disease locus telomeric to D4S412 (location score in log 10 = 4.60). Moreover, this study supports the view that ACH and HCH are genetically homogeneous in our series.

Achondroplasia↗
PubMed1992

Alport syndrome: a genetic study of 31 families.

Thirty one families with Alport syndrome including 3 families with associated syndromes were studied. The location of the COL4A5 gene, responsible for the Alport syndrome, was determined by linkage analysis with eight probes of the Xq arm and by a radiation hybrid panel. Concordant data indicated the localization of the Alport gene between DXS17 and DXS11. Four deletions and one single base mutation of the COL4A5 gene were detected. Homogeneity tests failed to show any evidence of genetic heterogeneity superimposed on clinical heterogeneity for ophthalmic signs and end-stage renal disease age.

Adolescent↗
PubMed1992

Alport syndrome and diffuse leiomyomatosis: deletions in the 5' end of the COL4A5 collagen gene.

Alport syndrome (AS) is an hereditary glomerulonephritis that is mainly inherited as a dominant X-linked trait. Structural abnormalities in the type IV collagen alpha 5 chain gene (COL4A5), which maps to Xq22, have recently been detected in several patients with AS. The association of AS with diffuse esophageal leiomyomatosis (DL) has been reported in 24 patients, most of them also suffering from congenital cataract. The mode of transmission and the location of the gene(s) involved in this association have not been elucidated. Southern blotting using cDNA probes spanning the whole COL4A5 and a 5' end COL4A5 genomic probe showed that three out of three patients with the DL-AS association had a deletion in the 5' part of the COL4A5 gene extending beyond its 5' end. This indicates that the same gene, COL4A5, is involved in classical AS and in DL-AS and that the transmission of DL-AS is X-linked dominant. These results also suggest that leiomyomatosis might be due to the alteration of a second gene involved in smooth muscle cell proliferation, which is located upstream of the COL4A5 gene, and that there might be a contiguous gene deletion syndrome, involving at least the genes coding for congenital cataract, DL and AS.

Adolescent↗
PubMedDate not supplied

Haloperidol treatment selectively affects expression of Galpha(i)3 subunit mRNA in specific regions of the rat brain.

Relative abundance of GTP binding protein mRNA coding for subunits alpha(i)1, alpha(i)2 and alpha(i)3, and their changes induced with chronic blockade of D2 receptor by haloperidol were compared in the frontal cortex, striatum, hippocampus and cerebellar cortex of the rat using a specific method based on multiplex RT-PCR. Galpha(i) subtype 2 mRNA was the most abundant, followed by subtype 1 and subtype 3. The haloperidol treatment produced an area specific increase in Galpha(i)3 mRNA in the frontal cortex and a decrease of Galpha(i)3 in the striatum. After 8-day withdrawal period, haloperidol-induced,changes disappeared in the striatum but became accentuated in the frontal cortex. Changes in the relative expression of Galpha(i) subtypes may significantly influence long-lasting effects of chronic D2 receptor blockade.

Animals↗
PubMedDate not supplied

Adrenergic receptors' responsiveness after acute and chronic treatment with haloperidol in the presence of calcium channel blockade.

The effects of acute and chronic (14 days) treatment with haloperidol (0.5 mg/kg ip) given alone or 15 min after nifedipine (5 mg/kg ip) on responsiveness of the alpha1- and beta-adrenergic receptors was investigated ex vivo by measuring of the second messenger responses. The accumulation of inositol phosphate (IP) or cyclic AMP were measured in brain cortical slices challenged with noradrenaline or isoproterenol. The facilitatory effect of a single dose of haloperidol on IP accumulation (an increase by approximately 50%) was abolished by nifedipine pretreatment. After chronic treatment with haloperidol alone its facilitatory effect disappeared, but a treatment with haloperidol after nifedipine caused a significant increase in IP accumulation. No treatment affected the responses from beta-adrenoceptors. These data show that the action of chronically administered haloperidol may be changed by the concomitant calcium channel blockade that prevents development of adaptation to persistent presence of the drug.

Adrenergic alpha-Agonists↗
PubMedDate not supplied

[Molecular genetics of congenital skeletal dysplasias related to mutations of fibroblast growth factor receptors].

Fibroblast growth factor receptors belong to the family of a membrane bound tyrosine kinases, which respond to stimulation by the fibroblast growth factor family of cytokines. Signalling through fibroblast growth factor receptors regulates proliferation and differentiation of connective tissue cells. Disruption of these important processes during morphogenesis results in skeletal dysplasias. Mutations of the fibroblast growth factor receptors (1, 2 and 3) cause achondroplasia, Crouzon syndrome and Apert syndrome, which are amongst the most common congenital dysmorphic syndromes. There exists a correlation between the genotype and phenotype in fibroblast growth factor receptors related syndromes. This relation can be explained on the basis of molecular pathology of the receptor protein. An increased frequency of new mutations and exclusive paternal origin of mutated alleles is explained by the role of fibroblast growth factor signalling during spermatogenesis. The availability of molecular tests for fibroblast growth factor receptors related syndromes should facilitate the diagnostic accuracy of these pleiotropic diseases which is independent of expression variability.

Bone Diseases, Developmental↗