Trypsin in human milk

Summary Human milk trypsin was purified by adsorption chromatography on cellulose-bound 4-aminobenzamidine; its molecular weight was about 24,000 daltons. Its concentration determined by a radioimmunoassay varies between 2.9 and 5.6 g/l.     

Trypsin in human milk

Human milk trypsin was purified by adsorption chromatography on cellulose-bound 4-aminobenzamidine; its molecular weight was about 24,000 daltons. Its concentration determined by a radioimmunoassay varies between 2.9 and 5.6 micrograms/l.     

17-Hydroxycorticosteroids in human milk

Zusammenfassung Der Gehalt an freiem und gebundenem 17-Hydroxycorticosteroid wurde an 8 Muttermilchentnahmen nach einer Modifikation der Methode vonSilber undPorter geprüft. Der erhaltene Wert war nichtsignifikant niedrig. Auf einmalige intramuskuläre Injektion von 100 mg Cortison oder Hydrocortison erfolgte kein signifikanter Anstieg des Steroidwertes.     

Riboflavin enhancement of bilirubin photocatabolism in vivo

Zusammenfassung Intravenös verabreichtes Riboflavin-5-Monosodium-Phosphat-Salz (FMN) bewrikt eine beschleunigte Senkung des Plasma-Bilirubin-Spiegels bei Gunn-Ratten, wenn diese vorher fluoreszierendem Tageslicht (300 Kerzen) ausgesetzt waren. FMN beschleunigt ausserdem den Photozerfall in vitro. Die Bilirubin-Phototherapie durch Injektion eines geeigneten Katalysators wird diskutiert.

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Albino Gunn rat breeding stock was obtained through the courtesy of Dr.Lois Johnson, Pennsylvania Hospital, Philadelphia, Pennsylvania, and hooded Gunn rat breeding stock through the courtesy ofMr. Richard L. Pierson, Rodent and Rabbit Production Section, National Institutes of Health, Bethesda, Maryland. This investigation was supported in part by research grant HD 05745-01 from the National Institute of Child Health and Human Development.     

Occurrence of DDT and BHC residues in human milk in India

Summary Samples of human milk from Punjab, India have shown the presence of DDT and BHC residues in amounts greater than those reported from most of the other countries.This research has been financed in part by a grant made by the United States Department of Agriculture, Agricultural Research Service authorized by Public Law 480.     

Occurrence of DDT and BHC residues in human milk in India

The presence of pesticide residue of DDT and of BHC were determined in 1979 in samples of milk from 75 lactating mothers from Punjab, within a week after delivery. DDT and BHC residues were found present in all 75 samples collected. Recovery of isomers of BHC and metabolites/isomers of p.p'-DDT from the spiked samples was above 80%. The mean level of DDT residue was 0.51 ppm, which is more than the level reported from the U.S., Canada, Europe and Australia, but less than the level found in Guatemala. BHC residues also were higher than those found in other countries, with the exception of Japan. DDT level of 0.5 ppm in milk represents an infant intake of 0.09 mg/kg/day, which is 18 times the acceptable daily intake (0.005 mg/kg/day) recommended by the WHO. Acceptable daily intake of BHC has not yet been established.     

Characterization of a thermosensitive protein from human milk whey

Summary A human milk whey protein, which aggregates at room temperature and resolubilizes when cooled, was purified by chromatography on hydroxyapatite. The present study demonstrated that the thermosensitive protein is a nonphosphorylated form of -casein.We thank Dr J.J. Pahud for preparation of anti Na-caseinate antiserum and Miss D. Fumeaux for technical assistance.     

Anti-bovine beta-lactoglobulin antibodies react with a human lactoferrin fragment and bovine beta-lactoglobulin present in human milk

Human milk samples react against anti-bovine beta-lactoglobulin rabbit antibodies, as measured by a competitive radioimmunoassay. Immunoreactivity was positive even in milk from mothers consuming a diet free of cow's milk. An increase with a diet rich in cow's milk proteins was detected by immunoelectrophoresis. The human milk fraction cross-reacting with anti-bovine beta-lactoglobulin antibodies corresponds to the 20 kDa fragment from the N-terminal end of human lactoferrin. Three regions of this fragment exhibit sequence homology with a sequence contained in cow's beta-lactoglobulin (between residues 124 and 141).     

Comparative analysis of human milk and human blood plasma by means of diffusion-in-gel methods

Zusammenfassung Mit Hilfe von Immunoelektrophorese und Doppeldiffusiontechnik wurden in Humanmilch an Blutplasmaproteinen serologisch identifiziert: Praealbumin, Albumin, Acid Seromucoid, ₁-Glykoprotein (3·5 S), Coeruloplasmin, Haptoglobin, ₂- oder-Lipoprotein, Transferrin, Fibrinogen, _2A-Globulin, _2M-Globulin und-Globulin.     

Amino acid incorporation by human milk fat globules membranes (author's transl)]

Human milk fat globule membranes (MFGM) can incorporate radioactive 14C amino acids in a hot trichloracetic acid-insoluble material. Aspecific adsorption and bacterial contamination are unlikely. The products of protein synthesis were analyzed by polyacrylamide gel electrophoresis in sodium dodecyl sulfate or by action of proteolytic enzymes. Various inhibitors of protein synthesis were assayed. Fragments of rough endoplasmic reticulum or mitochondria could be involved in this incorporation.     

Riboflavin in the blood serum,the skin and the venom of some snakes of Burma

Zusammenfassung Es wurden sowohl giftige als auch ungiftige Schlangen aus Burma auf den Gehalt an Flavinen in Blut und Haut untersucht.     

Production of pharmaceutical proteins in milk

There is every reason to expect that it will be possible within the next few years to begin to use farm animals to produce large quantities of some of the human proteins that are needed for the treatment of disease. Revolutionary new opportunities for the production of novel proteins in milk have been created by the development of methods for gene transfer. Exploitation of these opportunities depends upon selection and cloning of milk protein genes and identification of the sequences that govern tissue specific hormonally induced expression in the mammary gland. Studies with three genes, ovine beta-lactoglobulin, rat beta-casein and whey acidic protein of rat and mouse, suggest that they may all meet this requirement. Fragments of the ovine beta-lactoglobulin, murine whey acidic protein and rabbit beta-casein genes have directed production of novel proteins in the milk of transgenic mice, sheep, rabbits and pigs. The proteins were biologically active and usually co-migrated with authentic proteins. In early experiments, protein concentration was low, but our recent observations suggest that fusion genes containing genomic clones direct production of concentrations of protein that are suitable for commercial exploitation. In the longer term, two approaches may offer the potential of more reliable expression. Control elements capable of directing expression that is independent of site of insertion of the gene, but dependent on the number of copies of the gene, have been identified for a small number of genes. The availability of such elements for the milk protein genes would increase the reliability of gene expression considerably. Alternatively, targeted mutation of genes may allow the insertion of coding sequences within an existing gene so avoiding position effects.     

Production of pharmaceutical proteins in milk

There is every reason to expect that it will be possible within the next few years to begin to use farm animals to produce large quantities of some of the human proteins that are needed for the treatment of disease. Revolutionary new opportunities for the production of novel proteins in milk have been created by the development of methods for gene transfer. Exploitation of these opportunities depends upon selection and cloning of milk protein genes and identification of the sequences that govern tissue specific hormonally induced expression in the mammary gland. Studies with three genes, ovine -lactoglobulin, rat -casein and whey acidic protein of rat and mouse, suggest that they may all meet this requirement. Fragments of the ovine -lactoglobulin, murine whey acidic protein and rabbit -casein genes have directed production of novel proteins in the milk of transgenic mice, sheep, rabbits and pigs. The proteins were biologically active and usually co-migrated with authentic proteins. In early experiments, protein concentration was low, but our recent observations suggest that fusion genes containing genomic clones direct production of concentrations of protein that are suitable for commercial exploitation. In the longer term, two approaches may offer the potential of more reliable expression. Control elements capable of directing expression that is independent of site of insertion of the gene, but dependent on the number of copies of the gene, have been identified for a small number of genes. The availability of such elements for the milk protein genes would increase the reliability of gene expression considerably. Alternatively, targeted mutation of genes may allow the insertion of coding sequences within an existing gene so avoiding position effects.