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J Denman

Publications and source records attributed to J Denman.

6 recordsLinked to original sources
PubMed1994

Lateral cradling preferences in humans (Homo sapiens): similarities within families.

Women (Homo sapiens) tend to cradle infants on the left side of the body. We report the results of a survey of family photograph albums. We found that left-side cradling frequencies (LCFs) are higher in women than in men and that there are strong significant correlations between the LCFs of mothers and daughters, sisters, and maternal grandmothers and granddaughters. There may be a genetic influence on lateral cradling tendencies; women's left-side cradling preferences were found to be repeated with subsequent children. Heritability of women's LCF has an upper limit of 0.82, and the regression of daughters' mean LCF on mothers' LCF gives a heritability of 0.93 +/- 0.29. The data may be interpreted in two ways: There may be sex-limited genes (i.e., genes that express themselves only in women) for lateral cradling preferences, or women may learn cradling preferences from their mothers and other female relatives.

Animals↗
PubMed1994

Induction of human tissue plasminogen activator in the mammary gland of transgenic goats.

Three transgenic females from a first generation transgenic male were induced to lactate between 11 and 12 months of age using a series of estrogen and progesterone injections. The milk contained human longer acting tissue plasminogen activator (LAtPA) at comparable concentrations (1-3 mg/ml) as occurred in the original founder female. In addition, the transgenic male was induced with a hormonal regime and was shown to produce 0.85 mg/ml of LAtPA. Milk protein gels indicated that the milk products (casein, IgG) were essentially normal. These experiments show that expression data for this vector can be evaluated in a shorter period of time in dairy goats than would be required through normal gestation and lactation schedules and can be used to identify the relative expression of transgenes in mammary tissue that would occur during normal lactation.

Animals↗
PubMed1991

Transgenic production of a variant of human tissue-type plasminogen activator in goat milk: generation of transgenic goats and analysis of expression.

We report the first successful production of transgenic goats that express a heterologous protein in their milk. The production of a glycosylation variant of human tPA (LAtPA--longer acting tissue plasminogen activator) from an expression vector containing the murine whey acid promoter (WAP) operatively linked to the cDNA of a modified version of human tPA was examined in transgenic dairy goats. Two transgenic goats were identified from 29 animals born. The first animal, a female, was mated and allowed to carry the pregnancy to term. Milk was obtained upon parturition and was shown to contain enzymatically active LAtPA at a concentration of 3 micrograms/ml.

Animals↗
PubMed1991

Transgenic expression of a variant of human tissue-type plasminogen activator in goat milk: purification and characterization of the recombinant enzyme.

A glycosylation variant of human tissue-type plasminogen activator (tPA) designated longer-acting tissue-type plasminogen activator (LAtPA) was extensively purified from the milk of a transgenic goat by a combination of acid fractionation, hydrophobic interaction chromatography and immunoaffinity chromatography. This scheme provided greater than 8,000-fold purification of the protein, a cumulative yield of 25% and purity greater than 98% as judged by SDS gel electrophoresis. SDS gel electrophoresis revealed that the transgenic enzyme was predominantly the "two chain" form of the protease. The specific activity of the purified transgenic protein, based on the average of the values obtained for three different preparations, was 610,000 U/mg as judged by amidolytic activity assay. This was approximately 84% of the value observed for the recombinant enzyme produced in mouse C127 cells. Analysis of the transgenic protein indicated that it had a significantly different carbohydrate composition from the recombinant enzyme produced in C127 cells. Molecular size analysis of the oligosaccharides from the transgenic and C127 cell-derived LAtPA preparations confirmed their differences and showed that the mouse cell-derived preparation contained larger, complex-type N-linked oligosaccharide structures than the material produced in goat mammary tissue.

Animals↗
PubMed1990

Cloning and expression of peptide-N4-(N-acetyl-beta-D-glucosaminyl)asparagine amidase F in Escherichia coli.

The peptide-N4-(N-acetyl-beta-D-glucosaminyl) asparagine amidase F (PNGase F) gene from Flavobacterium meningosepticum was cloned into a high copy number Escherichia coli plasmid. Levels of PNGase F activity produced in cultures of the recombinant strain were up to 100-fold higher than those obtained in cultures of F. meningosepticum. The complete PNGase F gene sequence was determined. Comparison of the predicted amino acid sequence of pre-PNGase F to the N-terminal sequence of the native mature enzyme indicates that the protein is synthesized with a 40-amino acid signal sequence that is removed during secretion in F. meningosepticum. The recombinant PNGase F produced in E. coli is a mixture of products comprised predominantly of two proteins with molecular masses of 36.3 and 36.6 kDa. These proteins have a higher apparent molecular mass than the 34.7-kDa native enzyme. N-terminal amino acid sequencing demonstrated that these higher molecular mass products result from cleavage of the pre-PNGase F in E. coli upstream of the native N terminus. The PNGase F gene was engineered to encode a preenzyme that was processed in E. coli to give an N terminus identical to that of the native enzyme. Purified preparations of this form of recombinant PNGase F were shown to be suitable for glycoprotein analyses since they possess no detectable endo-beta-N-acetylglucosaminidase F, exoglycosidase, or protease activity.

Amidohydrolases↗