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Biomedical subjects

J A Sorge

Publications and source records attributed to J A Sorge.

26 records · Page 2Linked to original sources
PubMed1989

Neonatal growth delay in alpha-1-antitrypsin disease. Influence of genetic background.

We have developed a transgenic mouse strain, Z#2, which represents a model for alpha 1-protease inhibitor (alpha 1-antitrypsin: alpha 1-Pi)-associated liver disease (Dycaico et al., 1988). Fifteen percent of human infants with alpha 1-Pi disease develop non-viral hepatitis which is sometimes associated with growth retardation. Such hepatitis and growth retardation tend to occur in a subset of families with other alpha 1-Pi affected members who have had non-viral hepatitis. The Z#2 mouse strain exhibits non-viral hepatitis and growth retardation. This phenotype is more pronounced in transgenic offspring of crosses between Z#2 mice and DBA/2J inbred mice, and less pronounced in transgenic offspring of crosses between Z#2 and CBA/J inbred mice. Such phenotypic differences resemble the phenotypic differences seen in human families with alpha 1-Pi-associated liver disease.

Animals↗
PubMed1988

Lambda ZAP: a bacteriophage lambda expression vector with in vivo excision properties.

A lambda insertion type cDNA cloning vector, Lambda ZAP, has been constructed. In E. coli a phagemid, pBluescript SK(-), contained within the vector, can be excised by f1 or M13 helper phage. The excision process eliminates the need to subclone DNA inserts from the lambda phage into a plasmid by restriction digestion and ligation. This is possible because Lambda ZAP incorporates the signals for both initiation and termination of DNA synthesis from the f1 bacteriophage origin of replication (1). Six of 21 restriction sites in the excised pBluescript SK polylinker, contained within the NH2-portion of the lacZ gene, are unique in lambda ZAP. Coding sequences inserted into these restriction sites, in the appropriate reading frame, can be expressed from the lacZ promoter as fusion proteins. The features of this vector significantly increase the rate at which clones can be isolated and analyzed. The lambda ZAP vector was tested by the preparation of a chicken liver cDNA library and the isolation of actin clones by screening with oligonucleotide probes. Putative actin clones were excised from the lambda vector and identified by DNA sequencing. The ability of lambda ZAP to serve as a vector for the construction of cDNA expression libraries was determined by detecting fusion proteins from clones containing glucocerbrosidase cDNA's using rabbit IgG anti-glucocerbrosidase antibodies.

Actins↗
PubMed1988

In vitro synthesis of infectious retroviral RNA.

A plasmid was constructed in which a T7 RNA polymerase promoter was placed upstream of a recombinant amphotropic retrovirus genome containing a selectable neomycin resistance gene. To test the infectivity of the RNA produced by T7 RNA polymerase in vitro, the RNA was microinjected into the nuclei of psi 2 packaging cells. Infectious particles conferring G418 resistance were released.

Base Sequence↗
PubMed1987

Transfection of a factor-dependent cell line with the murine interleukin-3 (IL-3) cDNA results in autonomous growth and tumorigenesis.

The factor dependent murine myeloid line 32D c15 was transfected by electroporation with a murine interleukin-3 (IL-3) cDNA expression plasmid bearing the murine metallothionein-I promoter element. Factor-independent cell growth was readily obtained, and was shown to be accompanied by the production of biologically active IL-3. Three cell lines, growing autonomously and secreting IL-3 activity into their supernatants were established. S-1 nuclease analysis was employed to demonstrate that the introduced plasmid and not the endogenous IL-3 gene was the source of the IL-3 in one of these lines. The transfected IL-3 secreting cell lines, but not the parental factor-dependent 32D c15 cells, were uniformly able to induce tumors in syngeneic mice. These results indicate that the conversion to a malignant phenotype of a "partially transformed" cell line may be achieved by one additional dominant genetic event, such as the acquisition of autocrine growth factor secretion.

Animals↗
PubMed1987

An embryonic DNA-binding protein specific for the promoter of the retrovirus long terminal repeat.

Retrovirus expression is restricted in embryonal carcinoma (EC) cells but not in many differentiated cell lines. We used a very sensitive gel retardation assay to detect sequence-specific DNA-binding proteins in crude nuclear extracts obtained from EC and differentiated cells. Four binding sites were mapped in the noncoding sequences of the amphotropic murine leukemia virus. Strong binding to the CCAAT consensus sequence located in the promoter was specifically observed with EC nuclear extract. The binding protein is called EPBF (embryonal promoter-binding factor), and it is a candidate for the repressor of retrovirus transcription.

Animals↗
PubMed1987

The human glucocerebrosidase gene has two functional ATG initiator codons.

Gaucher disease is due to a deficiency in the activity of the enzyme glucocerebrosidase. Glucocerebrosidase is a lysosomal enzyme that presumably requires a signal peptide for transport across the membrane of the rough endoplasmic reticulum and glycosylation for transport into lysosomes. Human glucocerebrosidase cDNA contains two potential ATG start codons in its long open reading frame. The signal peptides that are initiated from each ATG are quite different in their hydrophobicity. We demonstrate that either ATG can function independently to produce active glucocerebrosidase enzyme in cultured fibroblasts. The glucocerebrosidase activity produced from translation products initiated at either ATG is found predominantly in the lysosomes.

Amino Acid Sequence↗
PubMed1986

A conserved human germline V kappa gene directly encodes rheumatoid factor light chains.

The full-length gene that encodes the light chain variable regions of an idiotypically related group of human IgM kappa rheumatoid factors (RFs) has been cloned and sequenced. The deduced amino acid sequence is identical to four separate RF proteins. These results prove that genes capable of encoding human anti-IgG autoantibody light chains without any somatic mutation are present in the kappa gene repertoire of normal people.

Amino Acid Sequence↗