| 61. |
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| 62. |
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| 63. |
- Björk, Glenn R, et al.
(author)
-
Prevention of translational frameshifting by the modified nucleoside 1-methylguanosine
- 1989
-
In: Science. - 0036-8075 .- 1095-9203. ; 244:4907, s. 986-989
-
Journal article (peer-reviewed)abstract
- The methylated nucleoside 1-methylguanosine (m1G) is present next to the 3' end of the anticodon (position 37) in all transfer RNAs (tRNAs) that read codons starting with C except in those tRNAs that read CAN codons. All of the three proline tRNA species, which read CCN codons in Salmonella typhimurium, have been sequenced and shown to contain m1G in position 37. A mutant of S. typhimurium that lacks m1G in its tRNA when grown at temperatures above 37 degrees C, has now been isolated. The mutation (trmD3) responsible for this methylation deficiency is in the structural gene (trmD) for the tRNA(m1G37)methyltransferase. Therefore, the three proline tRNAs in the trmD3 mutant have an unmodified guanosine at position 37. Furthermore, the trmD3 mutation also causes at least one of the tRNAPro species to frequently shift frame when C's are present successively in the message. Thus, m1G appears to prevent frameshifting. The data from eubacteria apply to both eukaryotes and archaebacteria.
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| 64. |
- Björkman, Sven, et al.
(author)
-
Thermic and tremorogenic effects of thyroliberin (TRH) in reserpine-treated mice--the non-involvement of GABA-ergic mechanisms.
- 1981
-
In: Journal of Pharmacy and Pharmacology (JPP). - : Oxford University Press (OUP). - 0022-3573 .- 2042-7158. ; 33:9, s. 580-585
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Journal article (peer-reviewed)abstract
- Administration of thyroliberin (TRH) to reserpinized mice causes tremor and counteracts the hypothermia in a dose-dependent fashion. The thyroliberin response is inhibited by gamma-hydroxybutyric acid (GHB) and baclofen, but not by other, more specific GABA-ergic agents, such as THIP, gamma-acetylenic GABA, and sodium valproate. Picrotoxin neither potentiates nor inhibits the thyroliberin actions. Nor are the thyroliberin effects dependent on cholinergic, monoaminergic or histaminergic mechanisms. The results repudiate a current hypothesis, that the peptide actions may be mediated by GABA-ergic pathways in the brain.
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| 65. |
- Björkstén, B, et al.
(author)
-
Collecting and banking human milk : to heat or not to heat?
- 1980
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In: British medical journal. - 0007-1447. ; 281:6243, s. 765-9
-
Journal article (peer-reviewed)abstract
- Data on human breast milk and its handling when fed to babies who cannot be breast-fed were reviewed to determine whether the method of processing and storage affected the properties of the milk. Breast milk is normally contaminated by potential pathogens, which seem to produce no ill effects, but it also contains antimicrobial properties which protect against infection. The evidence suggests that pasteurisation not only eliminates pathogenic bacteria but also damages bacteriostatic mechanisms, so making the milk more susceptible to later contamination. Pasteurisation also affects the nutritional properties of milk. Freezing has little effect on milk proteins, while a study on the effect of refrigeration showed that there was little bacterial growth at temperatures below 8 degrees C. Several years' experience of feeding donated raw milk to newborn infants has confirmed that it produces no ill effects. These findings suggest that pasteurisation of donated breastmilk is unnecessary, and it is not recommended, while the decision whether or not to freeze the milk may be made on practical grounds. Raw breast milk can be safely stored at 4-6 degrees C for 72 hours.
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| 66. |
- Blind, Per Jonas, et al.
(author)
-
Carboxylic ester hydrolase : a serum marker of acute pancreatitis
- 1987
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In: Pancreas. - 0885-3177 .- 1536-4828. ; 2:5, s. 597-603
-
Journal article (peer-reviewed)abstract
- By use of an enzyme-linked immunosorbent assay we established serum reference values of carboxylic ester hydrolase, a pancreatic secretory lipolytic enzyme, and explored to see if a raised serum level is indicative of acute pancreatitis. Postoperative elevation of carboxylic ester hydrolase was observed in seven out of ten patients who underwent pancreatic surgery. Serum levels of carboxylic ester hydrolase and amylase were determined in 129 patients admitted due to abdominal emergency conditions. Amylase was elevated in 27 patients, and in 20 of these raised carboxylic ester hydrolase levels affirmed the diagnosis acute pancreatitis. In five out of the seven patients with elevated amylase alone no etiologic factor of acute pancreatitis was found. Another 11 patients had raised carboxylic ester hydrolase levels without concomitant elevation of amylase. In all these patients, a likely cause of pancreatic inflammation was identifiable. Hence, a raised carboxylic ester hydrolase level, even in presence of normal amylase, could be indicative of acute pancreatic inflammation.
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| 67. |
- Bläckberg, L, et al.
(author)
-
Bile-salt-stimulated lipase in human milk : evidence for its synthesis in the lactating mammary gland.
- 1987
-
In: FEBS Letters. - 0014-5793 .- 1873-3468. ; 217:1, s. 37-41
-
Journal article (peer-reviewed)abstract
- Human milk contains many enzymes and other biologically active proteins. One of the enzymes, the bile salt-stimulated lipase, constitutes as much as 1% of the milk proteins. Its importance for efficient utilization of milk lipids by the breast-fed infant is now well established. However, whether the lipase protein is a product of protein synthesis within the mammary gland has up till now been an unanswered question. Using biopsy material from lactating human mammary gland we have now demonstrated that the enzyme is synthesized within the gland. This was done by immunoprecipitation of [35S]methionine-labelled protein from tissue pieces. By activity determination we could also determine the amount of enzyme stored in the gland. It was concluded that bile salt-stimulated lipase accounted for 1.3 micrograms/mg tissue protein. Finally, from this figure it could be calculated that about 10-15% of the total protein present in the tissue was milk protein.
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| 68. |
- Bläckberg, Lars, et al.
(author)
-
Further characterization of the bile salt-stimulated lipase in human milk
- 1983
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In: FEBS Letters. - : Wiley. - 0014-5793 .- 1873-3468. ; 157:2, s. 337-341
-
Journal article (peer-reviewed)abstract
- Bile salt-stimulated lipase is a milk enzyme unique to the higher primates. Its molecular and kinetic characteristics differ greatly from other lipolytic enzymes; e.g., pancreatic lipase and lipoprotein lipase. It has a much higher app. Mr, 310000 on gel filtration and 100000 after denaturation. It requires primary bile salts for optimal activity and bile salts also protect the enzyme from proteolytic and heat inactivation. It may, due to its low substrate specificity, contribute to the utilization of a variety of milk lipids. Since it lacks positional specificity, digestion of milk triglycerides should be complete, which may explain why fat absorption is more efficient in breast-fed than in formula-fed infants.
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| 69. |
- Bohlin, Leif, et al.
(author)
-
Cone-plate instrument for stress relaxation measurements
- 1980
-
In: Journal of Colloid and Interface Science. - : Elsevier. - 0021-9797 .- 1095-7103. ; 73:1, s. 61-65
-
Journal article (peer-reviewed)abstract
- An instrument for the measurement of stress relaxation in shear is described. The force is detected by a sensitive piezoresistive pressure transducer. The requirement of constant strain can be fulfilled within less than 1%. Preset values of shear strain can be imposed on the sample within 0.1 sec. This instrument is suitable for soft solids and elastic liquids with a lower limit of ∼ 1 sec for the relaxation time. Results are given for wheat flour dough, a gelatinous deoxycholate complex and a gelatin gel. The instrument is simple, robust, and reliable, as well as inexpensive.
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| 70. |
- Borg, H, et al.
(author)
-
Evidence for IFN-beta heterogeneity in a substrain of Namalwa cells.
- 1985
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In: Applied Biochemistry and Biotechnology. - 0273-2289 .- 1559-0291. ; 11:2, s. 111-22
-
Journal article (peer-reviewed)abstract
- A substrain of Namalwa cells, denoted substrain B, was grown in fermentors up to the 100-L scale, and was induced with Sendai virus to produce interferon (IFN). The titer of the crude IFN varied extensively between different batches; part of the variation was caused by a differential expression of IFN-alpha and IFN-beta. More than 80% of the IFN activity was IFN-beta by several criteria. A two-step purification procedure was developed and the resulting preparation had a specific activity of approximately 10(6) U/mg protein. The IFN-beta type was found to be heterogeneous, and could be separated into several components, which probably represented post-translational modifications of one molecule.
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