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M Mottes

Publications and source records attributed to M Mottes.

49 records · Page 3Linked to original sources
PubMed1990

Segregation analysis of dominant osteogenesis imperfecta in Italy.

We have performed linkage analysis in seven Italian families, in which mild osteogenesis imperfecta (OI) segregated as a dominant trait, by means of six DNA restriction fragment length polymorphisms (RFLPs) of type I collagen genes. OI type I was linked to the alpha 1(I) gene (COL1A1) in two families, and to the alpha 2(I) gene (COL1A2) in one family. OI type IV segregated with COL1A2 in two families. In two OI type I families, the molecular genetic data were insufficient for exclusion of one gene. Four DNA polymorphisms were particularly informative for cosegregation analysis of OI in Italian kindreds.

Adult↗
PubMed1989

Haplotype frequencies of the collagen type-I genes in the Italian population.

We have determined the frequencies of six restriction fragment length polymorphisms (RFLPs) of type-I collagen genes in a random sample of 100 subjects. Alpha 1 gene (COL1A1) DNA polymorphisms, FG2/MspI, 2FC6/RsaI, and NST70/RsaI, had polymorphism information content (PIC) values of 0.35, 0.32, and 0.26, respectively. Alpha 2 gene (COL1A2) RFLPs, NJ3/EcoRI, Hf32/RsaI, and Hf32/MspI had PIC values of 0.36, 0.35, and 0.25, respectively. The combined haplotype PIC values were 0.71 at the COL1A1 locus and 0.73 for COL1A2. Two COL1A1 and two COL1A2 RFLPs were more polymorphic than in the English population, making them better markers for the analysis of Italian families affected by osteogenesis imperfecta and some other inherited collagen diseases.

Blotting, Southern↗
PubMed1988

Expression of hepatitis B surface antigen in human cells by a recombinant BK virus DNA vector.

The construction of the first stable human cell lines that express and secrete authentic hepatitis B virus surface antigen (HBsAg), using a BK virus (BKV) episomal plasmid vector, is described. The amount of HBsAg produced by BKV vectors (up to 600 ng/10(7) cells) was comparable to other eukaryotic vector systems. The level of HBsAg expression remained the same regardless of the orientation of the HBsAg gene, substitution of the HBsAg gene promoter with the mouse metallothionein I gene promoter or the tissue origin of the human cell lines used to establish stable cellular transformants. Northern blot analysis also indicated synthesis of normal HBsAg transcripts. Surprisingly, however, the vectors were maintained at far lower than expected copy number (one to five copies/cell). Reasons for this are discussed.

BK Virus↗
PubMed1987

Association of BK virus with human brain tumors and tumors of pancreatic islets.

BK virus (BKV) DNA was detected by Southern blot hybridization in 19 out of 74 (25.6%) human brain tumors and in 4 out of 9 (44.4%) human tumors of pancreatic islets. BKV DNA was free, in an episomal state and generally in a low copy number (0.2 to 2 genome equivalents per cell). Only occasional tumors contained 10 to 20 genome copies per cell. Viral DNA sequences integrated into cellular DNA were not detected. A number of tumors expressed BKV-specific RNA and T antigen. By transfection of total tumor DNA into human embryonic fibroblasts, viruses with the biological and antigenic properties of BKV were rescued from 6 brain tumors and from 2 tumors of pancreatic islets. Restriction endonuclease mapping of the genomes of the rescued viruses showed that they differ from wild-type BKV. They are all similar to each other and to BKV-IR, a virus previously rescued from a human tumor of pancreatic islets, suggesting the possible association of a BKV variant with specific types of human neoplasms. The significance of the relationship of these BKV variants to human tumors and their possible etiologic role in human oncogenesis are discussed.

Adenoma, Islet Cell↗
PubMed1984

A new type of EcoRI polymorphism of the human ribosomal DNA repeating unit revealed by analysis of cloned DNA fragments.

Several clones of rDNA have been isolated from an adult human liver DNA Charon 4A library by using cDNA probes synthesized from human 18S and 28S rRNA. The insert of one recombinant Charon 4A clone contained, besides the already known 5.7-kb EcoRI fragment of rDNA, comprising the major portion of the 18S rRNA gene and all the external transcribed spacer (ETS), a previously unidentified EcoRI fragment of rDNA of 8.5 kb in size. DNA transfer hybridization experiments utilizing EcoRI digests of the human DNA used to construct the library and of another human DNA showed the presence of the 8.5-kb EcoRI fragment in a minority of the rDNA repeats on the 5'-end side of the 5.7-kb fragment, thus defining a hitherto unidentified type of EcoRI polymorphism of these repeats.

Adult↗
PubMed1984

Possible hyperattenuation of transcription in the Escherichia coli hisG gene cloned in Bacillus subtilis.

The expression of the E. coli hisG gene in B. subtilis cells does not occur in spite of the faithful replication of the relevant DNA fragment cloned in this host by means of a plasmid vector, pHV14 , capable of replication in both B. subtilis and E. coli. Analysis of the RNA transcribed in vitro and in vivo by the B. subtilis RNA polymerase on the cloned hisG sequence indicates that in B. subtilis cells the physiological his operon promoter is not recognized. Transcription is initiated at many sites, some of which are located upstream of and some are located downstream of the his operon promoter. These "adventitious" promoters give rise to convergent transcription products which stop at, or in the vicinity of, the his operon attenuator sequence.

Bacillus subtilis↗
PubMed1979

Different specific activities of the monomeric and oligomeric forms of plasmid DNA in transformation of B. subtilis and E. coli.

(1) The low residual transforming activity in preparations of monomeric, supercoiled, circular (CCC) forms of the plasmids pC194 and pHV14 could be attributed to the presence in such isolates of a small number of contaminating multimeric molecules. (2) E. coli derived preparations of pHV14, as in vitro recombinant plasmid capable of replication in both E. coli and B. subtilis, contain oligomeric forms of plasmid DNA in addition to the prevalent monomeric CCC form. The specific transforming activity of pHV14 DNA for E. coli is independent of the degree of oligomerization, whereas in transformation of B. subtilis the specific activity of the purified monomeric CCC molecules is at least four orders of magnitude less than that of the unfractionated preparation. (3) Oligomerization of linearized pHV14 DNA by T4 ligase results in a substantial increase of specific transforming activity when assayed with B. subtilis and causes a decrease when used to transform E. coli.

Bacillus subtilis↗
PubMed1977

Restoration by T4 ligase of DNA sequences sensitive to "flush" cleaving restriction enzyme.

Fouteen "flush"-ended segments originate from the action of the restriction endonuclease Hae III of Haemophilus aegiptius on the DNA of the colicinogenic factor ColE 1 (A. Oka and M. Takanami, Nature, 264, 191, 1976). They are joined by the T4 polynucleotide ligase. The reaction can be monitored by gel electrophoresis, electron microscopy and resistance to phosphatase of the 5'-32P labelled ends. The joined products are a random recombination of the original segments, and can be cleaved by the same Hae III endonuclease to restore the exact electrophoretic pattern of the Hae III-cut ColE 1 DNA. In a properly diluted mixture of 5'-32P segments treated with T4 ligase, the level of phosphatase resistance is very close to the frequency of circle-formation as determined by electron microscopy: thus, the joining of the "flush"-ends involves the formation of circular structures covalently closed in both strands.

Coliphages↗
PubMedDate not supplied

Convergent transcription of the Escherichia coli hisG gene cloned in Bacillus subtilis stops in the vicinity of the attenuator.

A 5300-bp DNA segment containing the promoter, the attenuator and the first gene (hisG) of the Escherichia coli his operon has been inserted into an interspecific E. coli-Bacillus subtilis plasmid vector, pHV14. The resulting plasmid pPV48 restores the His+ phenotype to an E. coli hisG mutant, but fails to do so to a corresponding B. subtilis mutant. Experiments aimed at localizing the block to this heterologous expression in B. subtilis have shown that the enzymatic activity of the hisG+ gene product is neither detectable nor inhibited in crude extracts of B. subtilis cells harboring pPV48. Furthermore, electron microscopic, Southern blot and S1 mapping analysis of the transcripts produced in vitro and in vivo by B. subtilis RNA polymerase indicate that the hisG+ region is transcribed, but that the transcripts initiate at sites different from the his promoter, converge towards, and terminate in the vicinity of the attenuator.

Bacillus subtilis↗
PubMedDate not supplied

Allelic frequencies of FBN1 gene polymorphisms and genetic analysis of italian families with Marfan syndrome.

The fibrillin gene (FBN1) is the disease locus for Marfan syndrome. This disorder shows a high degree of clinical and allelic heterogeneity. Direct mutation screening has proven difficult and inefficient and at present cannot be utilized for routine analysis. In familial cases linkage analysis represents a useful tool for molecular diagnosis. We have determined the allelic frequencies of 5 polymorphic markers within the FBN1 locus in the Italian population and have successfully employed them for prenatal diagnosis and resolution of clinically equivocal cases.

Alleles↗
PubMedDate not supplied

Osteogenesis imperfecta: practical treatment guidelines.

Osteogenesis imperfecta (OI), an inherited connective tissue disorder of remarkable clinical variability, is caused by a quantitative or qualitative defect in collagen synthesis and is characterised by bone fragility. The number of fractures and deformities, and the age at which they begin greatly influence the prognosis and the achievement of walking and autonomy. A multidisciplinary team approach is essential for diagnosis, for communication with patient and parents, and to tailor treatment needs to the severity of the disease and the age of the patient. Three types of treatment are available: nonsurgical management (physical therapy, rehabilitation, bracing and splinting), surgery (intramedullary rod positioning, spinal and basilar impression surgery), and drugs to increase the strength of bone and decrease the number of fractures. An aggressive rehabilitative approach is indicated to optimise functional ability and walking capacity; appropriately timed surgery to insert intramedullary rods provides improved function of extremities. Despite a high rate of complications, intramedullary telescopic roding has proven to be the most successful method for preventing and correcting fractures and deformities of long bones, improving walking capability and leading to successful rehabilitation of even severely affected patients. Surgery may be required in patients with progressive spinal deformity and in those with symptomatic basilar impression. Hearing function, dentinogenesis imperfecta, cardiac and respiratory function, and neurological changes must be monitored. The causal defect of the disease cannot be corrected with medical treatment and, currently, only symptomatic therapy is available. In recent years growth hormone (GH) and bisphosphonate agents have been used in OI therapy. GH is beneficial in patients with moderate forms of OI, showing a positive effect on bone turnover, bone mineral density and height velocity rate. Bisphosphonates have proved beneficial in children with severe OI, increasing bone mineral density and reducing the fracture rate and pain with no adverse effects reported. These data require confirmation in double-blind controlled studies; however, bisphosphonates have markedly improved morbidity in patients with OI. Future developments in genetic therapy may be directed towards either replacing cells carrying the mutant gene with normal cells or silencing the mutant allele using antisense suppression therapy, thus transforming a biochemically severe form of OI into a mild form.

Child↗