Search PubMed⌕ Search

Biomedical subjects

U Friedrich

Publications and source records attributed to U Friedrich.

At least 91 records · Page 5Linked to original sources
PubMed1987

Coloboma and microphthalmos in chromosomal aberrations. Chromosomal aberrations and neural crest cell developmental field.

A survey of more than 500 reports on patients with autosomal chromosomal aberrations associated with microphthalmos and/or coloboma shows that these anomalies are unspecific. Anterior chamber anomalies were common as were abnormal ears, preauricular pits and tags, cleft lip-palate, micrognathia, urogenital malformations, congenital heart disease, atresia of the anus and minor malformations of the hands and feet. It is proposed that the chromosomal aberrations induce faulty development of neural crest cells and rostral neural plate derivatives.

Abnormalities, Multiple↗
PubMed1986

A comparison between flow cytometric ploidy investigation and chromosome analysis of 32 human colorectal tumors.

The correlation between flow cytometric ploidy investigation and classic chromosome analysis was studied in 32 human colorectal tumors. Flow cytometry was performed by nuclei isolation and DNA staining with ethidium bromide. Chromosome analysis was done after incubation with colcemid. In 12 cases, chromosome identification was possible by grouping according to the Denver system or by Q-banding. Generally, the measured DNA content corresponded well with the content expected from chromosome analysis, giving an average difference of 4%. In nine tumors, the measured DNA content was 4-18% higher than expected. Some of these discrepancies could be due to difficulties in identifying the corresponding cell populations in heterogeneous tumors. However, in general the number of cell populations and their quantitative representation by the two methods were statistically well correlated. The results indicate that flow cytometric ploidy investigation of colorectal tumors with the present technique is a reliable method, but also that a combination of both techniques may yield additional information about tumor cytogenetics.

Colonic Neoplasms↗
PubMed1986

The neuronal noradrenaline transport system of PC-12 cells: kinetic analysis of the interaction between noradrenaline, Na+ and Cl- in transport.

The uptake of 3H-noradrenaline into reserpine-pretreated PC-12 cells (a clonal cell line which possesses "uptake1") was abolished when at high extracellular Cl- all the extracellular Na+ was replaced by Tris+ and when at high extracellular Na+ all the extracellular Cl- was replaced by isethionate. Increases in the external Cl- concentration (at a fixed high Na+ concentration) progressively increased the uptake of 3H-noradrenaline. The same was found with increase in the external Na+ concentration (at a fixed high Cl- concentration). From the anions tested only Br- and SCN- were able to partially mimic the transport-stimulating effect of Cl- (with about 40% and 20% effectiveness, respectively). When chloride was replaced by nitrate or larger anions such as sulphate, methylsulphate or isethionate, virtually no transport of 3H-noradrenaline was observed. The initial rate of uptake of 3H-noradrenaline showed saturation with increasing concentrations of noradrenaline when determined at several fixed concentrations of either Na+ or Cl-. The apparent Km for noradrenaline transport (KmNA) progressively decreased and the VmaxNA increased with increases in the concentration of Na+ (at a high concentration of Cl-) or Cl- (at a high concentration of Na+). The stimulation of the initial rate of uptake of 3H-noradrenaline by increasing concentrations of either Na+ or Cl- obeyed saturation kinetics when determined at several concentrations of noradrenaline. The concentration of Na+ (or Cl-) which caused half-maximal stimulation of uptake (i.e., the apparent KmNa+ and the apparent KmCl-) decreased with increases in the concentration of noradrenaline. These results strongly suggest that Na+ and Cl- are co-transported with noradrenaline.

Animals↗
PubMed1986

Induction and characterization of antisera against terminal and internal peptides of SV40 large T antigen.

Thirteen synthetic peptides corresponding to different regions of the SV40 large T antigen were used as immunogens after coupling to a carrier protein. All peptide conjugates elicited sera that recognized the inducing peptide. In 10 cases the corresponding sites in the native large T antigen also were recognized, as determined by immunoprecipitation. The degree of recognition of the native protein varied between 0.5 and 80%, the most reactive sera being those induced by the terminal peptides. The ability of internal peptides to induce antibodies reactive with native large T antigen appeared to be correlated with peptide hydrophilicity and possibly atomic mobility. No such correlation was apparent with predicted features of secondary structure. The influence of peptide length on induction of protein-recognizing antisera will also be discussed.

Amino Acid Sequence↗
PubMed1986

Acetylcholinesterase activities in association with congenital malformation of the terminal ureter in infants and children.

Acetylcholinesterase activity was found to be higher than normal in intravesical segments of ureters taken from children with vesicoureteral reflux. The ratio of acetylcholinesterase activity to total cholinesterase activity was also found to be high. Acetylcholinesterase activity was normal in intravesical segments taken from the constricted area of ureters from children with obstructive megaureter but it was high in segments taken from the juxtavesical part, immediately adjacent to the constricted area. These findings complement histological studies which have revealed a hyperplasia of cholinergic nerve fibres in the tunica muscularis of reflux ureters whereas obstructive megaureters show a hypoplasia of the beta-adrenergic system.

Acetylcholinesterase↗
PubMed1986

Norrie's disease: delineation of carriers among daughters of obligate carriers by linkage analysis.

Norrie's disease is an X-linked disorder with congenital blindness. Carriers are clinically healthy, so that they are only identifiable when they are daughters of affected males, or mothers to affected males in whose families other males have Norrie's disease. Daughters of carriers have an á priori 50 per cent risk of being carriers themselves. We have recently found close linkage between the genes for Norrie's disease and the DXS7 locus, characterised by a DNA restriction fragment length polymorphism (RFLP), L1.28. In three informative families we show that this RFLP can help to delineate carriers from those of their female relatives who are homozygous for the normal gene.

Adult↗
PubMed1985

X-linked retinitis pigmentosa: linkage with the centromere and a cloned DNA sequence from the proximal short arm of the X chromosome.

A large Danish pedigree segregating for X-linked retinitis pigmentosa (RPX) (Warburg and Simonsen 1968) was restudied for linkage analysis. Using two markers, i.e. the DNA base sequence polymorphism presented by the probe L1.28 defining the chromosomal segment DXS7, and the C-banding heteromorphism (Xcen) (Friedrich 1982), we were able to localize the RPX gene in Xp close to the centromere rather precisely. The gene order could be deduced by three-point linkage analysis, and the gene distances were determined by pairwise analysis using the LIPED program (Ott 1974). Together with previously published data concerning the RPX:DXS7 linkage (Bhattacharya et al. 1984) a regional gene map is constructed. Xcen-11 cM-RPX-6 cM-DXS7.

Adolescent↗
PubMed1985

Close linkage between Norrie disease, a cloned DNA sequence from the proximal short arm, and the centromere of the X chromosome.

Norrie disease (ND) is an X-linked recessive disorder with congenital blindness (atrophia bulborum hereditaria, pseudoglioma). Six kindreds segregating for ND were studied for linkage with polymorphic markers of the human X chromosome. No recombination was observed between the ND-locus (NDP) and the DXS7 locus, the latter followed as a DNA-restriction fragment length polymorphism, detected by the recombinant DNA probe L1.28, and assigned to the region Xp11.2-Xp11.3. The maximum lod scores are zeta = 3.81 at theta = 0.00. Linkage data between NDP and the other genetic markers used in the present study are in keeping with this assignment of the mutation to the proximal Xp.

Adolescent↗
PubMed1985

Induction of malignant transformation by various chemicals in Balb/3T3 clone A31-1-1 cells and biological characterization of some transformants.

Balb/c A31-1-1 cells were used for the study of transformation induction by chemicals with different mutagenic specificities. We show that survival of these cells and therefore the calculated transformation frequency per cells at risk is dependent upon the cell density at the time of treatment. It is suggested that equal cell densities should be used for measuring survival values and transformation induction. The quantitative results obtained are discussed in the light of the known mutagenic mechanisms of the chemicals tested. We also characterized morphologically transformed foci induced by different chemicals with respect to some biological properties. Anchorage independence was determined by testing growth in soft agar, loss of contact inhibition was quantitated by measuring maximum cell densities and malignancy was tested by tumor induction in nude mice. Although no very close correlation between these parameters and morphology was observed, the most malignant clones are also the ones with the highest values in the other tests. Our data make one or few genetical targets for transformation induction likely. We therefore speculate that the diverse phenotypes obtained might be due to differential activation of one or very few transforming genes in these cells.

Animals↗
PubMed1985

[Operative therapy of a refluxing double ureter in childhood].

Surgical methods for repairing the bilateral vesico-ureteral reflux have to be adapted to the pathomorphological and pathodynamic variety of refluxing ureters. Ureteroureterostomy can be performed in the cranial section of the ureter in order to check the local situation of the kidney and its macroscopic structure. But the distal localisation of the uretero-ureteral anastomosis proves to be favourable too. The operation according to Politano-Leadbetter is the method of choice to correct the reflux. It is only in therapy-resistent pyuria with decompensation of the kidneys that temporary supravesical urine-derivation has turned out to be an advantage because the possibility of organ-conservation by surgery later is still preserved.

Child↗
PubMed1985

Familial cranial diabetes insipidus: a report of five families. Genetic, diagnostic and therapeutic aspects.

Five families were studied in which cranial diabetes insipidus occurred. In the pedigrees presented, the disease clearly followed an autosomal dominant mode of inheritance. Linkage analysis was performed in one large family by calculating lod scores for linkage between loci for cranial diabetes insipidus and 18 polymorphic markers and chromosome heteromorphisms. No significant genetic linkage was found and only one of the polymorphic markers gave a positive hint of linkage. A water deprivation test was performed in nine patients from three of the families and in healthy control subjects. The plasma concentration of arginine vasopressin was very low or undetectable in the patients, and unlike the control subjects did not increase significantly during water deprivation. Arginine vasopressin and serum osmolality (Sosm) were significantly positively correlated in the controls, but not in the patients. The results indicated that an arginine vasopressin-level lower than 2 pg/ml strongly suggests a diagnosis of cranial diabetes insipidus if at the same time Sosm is higher than 295 mosmol/kg. Studies with different intranasal dosages of 1-deamino-D-arginine-vasopressin (DDAVP) given once or twice a day showed that 20 micrograms effectively reduced urinary output and that administration once a day could be sufficient.

Adolescent↗
PubMed1984

Linkage studies in Menkes' disease. The Xg blood group system and C-banding of the X chromosome.

Menkes' disease is a rare, genetically determined disturbance of copper metabolism which is transmitted as an X-linked recessive character. By comparative gene mapping it can be suggested that the most likely localization of the gene for Menkes' disease is on the long arm of the human X chromosome close to band q 13. This regional assignment is supported by the present analysis of the genetic relationship between the Menkes locus, the Xg locus, and the centromere in five Danish families. The evidence suggests close linkage between the Menkes locus and the centromere. The most likely value of the recombination fraction is 0.05 and the maximum lod score is above the conventional +3 limit. Linkage analysis of the Menkes locus and the Xg locus showed a recombination value of 0.24, but the maximum conditional score is 0.28, which is far below the conventional +3 limit. The present study demonstrates a successful application of a chromosomal morphological marker in linkage analysis and carrier detection of a single gene disorder. The close linkage between the gene for Menkes' disease and the centromere region was used to improve the classification of several females in whom the copper uptake into cultured fibroblasts was either inconclusive or not available.

Blood Group Antigens↗