Nerina Savage

Nuclear internalisation and DNA binding activities of interleukin-1, interleukin-1 receptor and interleukin-1/receptor complexes

This paper presents evidence to suggest that interleukin-1 alpha as a complex with its receptor is able to express DNA binding activity. Both the interleukin-1/receptor complex and the interleukin-1 receptor appear to be able to bind to DNA, however interleukin-1 on its own showed no binding activity. Interleukin-1 was found to be internalised into the nuclei of all cells examined (EL4, MEL, HL-60, K562, THP-1 and Jurkat cells). The data suggest the possible modulation of genes by interaction of interleukin-1/receptor complexes with DNA structures.

Respiratory activities of subsarcolemmal and intermyofibrillar mitochondrial populations isolated from denervated and control rat soleus muscles

Ultraturrax and Nagarse released populations of mitochondria isolated from control and day 21 denervated rat soleus muscle were characterized with respect to their oxidative phosphorylation, ADP translocase and ATPase activities. Both Ultraturrax and Nagarse released mitochondrial populations displayed lower capacities for oxidative phosphorylation; lower ADP translocase activities and higher Mg2+ stimulated ATPase activities than their corresponding controls. For both the denervated and control states, the Nagarse-released mitochondrial populations displayed significantly higher respiratory activities than the Ultraturrax released fractions. The significance of these findings is discussed with regard to the process of mitochondrial respiratory control. In addition the role of mitochondrial dysfunction in denervation muscular atrophy is assessed.

Dose-dependent reduction of lipopolysaccharide pyrogenicity by polymyxin B

Lipopolysaccharides (LPS) from Gram-negative bacteria are potent pyrogens in mammals. Polymyxin B (PB), a cationic polypeptide antibiotic, binds lipid A, the active moiety of LPS, with high affinity and abrogates several biological responses to LPS. We studied the effect of PB on pyrogenicity of purified LPS from E. coli 0111:B4 in rabbits. PB reduced the pyrogenic response to LPS in a dose-dependent manner at mass ratios (PB:LPS) from 5:1 to 100:1. Previous reports have suggested that PB is effective only at much higher doses. In our hands, PB itself is pyrogenic, unless previously gamma-irradiated. Our results confirm in vivo the anti-endotoxic action of PB.

Treatment of Normal Skeletal Muscle with FK506 or Rapamycin Results in Halothane-induced Muscle Contracture

Background FKBP12 is a protein that is closely associated with the ryanodine receptor type 1 of skeletal muscle and modulates Ca2+ release by the channel. The immunosuppressants FK506 and rapamycin both bind to FKBP12 and in turn dissociate the protein from the ryanodine receptor. By treating healthy human skeletal muscle strips with FK506 or rapamycin and then subjectin the strips to the caffeine-halothane contracture test, this study determined that FK506 and rapamycin alter the sensitivity of the muscle strip to halothane, caffeine, or both. Methods Skeletal muscle strips from 10 healthy persons were incubated in Krebs medium equilibrated with a 95% oxygen and 5% carbon dioxide mixture, which contained either 12 [micro sign]M FK506 (n = 8) or 12 [micro sign]M rapamycin (n = 6), for 15 min at 37 [degree sign]C. The strips were subjected to the caffeine-halothane contracture test for malignant hyperthermia according to the European Malignant Hyperthermia Group protocol. Results Treatment of normal skeletal muscle strips with FK506 and rapamycin resulted in halothane-induced contractures of 0.44 +/- 0.16 g and 0.6 +/- 0.49 g, respectively, at 2% halothane. Conclusions The results obtained show that pre-exposure of healthy skeletal muscle strips to either FK506 or rapamycin is sufficient to give rise to halothane-induced contractures. This is most likely caused by destabilization of Ca2+ release by the ryanodine receptor as a result of the dissociation of FKBP12. This finding suggests that a mutation in FKBP12 or changes in its capacity of blind to the ryanodine receptor could alter the halothane sensitivity of the skeletal muscle ryanodine receptor and thereby predispose the person to malignant hyperthermia.

Sequential development of glycolytic competence in the muscles of worker honeybees

Abstract 1. 1. The activities of hexokinase, cytoplasmic glycerol 3-phosphate dehydrogenase and lactate dehydrogenase were measured in mandibular and thoracic muscles of worker honeybees of various ages. 2. 2. A dramatic rise in hexokinase and glycerol 3-phosphate dehydrogenase activities occurs in mandibular muscle just prior to emergence from the sealed cells but only develops in thoracic muscle following emergence. Lactate dehydrogenase remains low for both muscles. 3. 3. Both mandibular and thoracic muscles thus operate aerobically for the period considered.

Effect of different dietary fats on oxygen consumption and on serum lipid levels in the baboon (Papio ursinus).

In herbivores such as the rabbit the regulation is easily overloaded; the addition of large amounts of cholesterol to the diet may result in a tenfold increase in the level of cholesterol in the serum. Even in omnivores such as poultry, dietary cholesterol causes a marked rise in serum cholesterol (March, Biely & Lindsay, 1964). Also in man, recent experiments have clearly shown that an excess of dietary cholesterol may raise the level of serum cholesterol (Connor, Stone & Hodges, 1964; Connor, Hodges & Bleiler, 1961 a, b ; Erickson, Coots, Mattson & Kligman, 1963). It can be accepted then that there is a cholesterol-regulating mechanism, easily overloaded in some animals and much more stable in others. For some years it has been known that an excess of dietary fats can also affect the concentration of cholesterol in the blood ; saturated fatty acids raise serum cholesterol level whereas polyunsaturated fatty acids lower it (Kinsell, Michaels, Friskey & Splitter, 1958; Bronte-Stewart, Antonis, Eales & Brock, 1956; Ahrens, Hirsch, Insull, Tsaltas, Blomstrand & Peterson, 1957). Little is known about the mechanism of this effect. We wished to investigate whether excess of saturated or, alternatively, polyunsaturated fat in the diet had some further action on a mammal in addition to the well-known effect on lipid levels. We have therefore studied the effect of such diets on basal oxygen consumption. We have used primates because, like man, they are omnivorous and are thus more likely to respond similarly to changes in diet. Two groups of baboons were studied. One group was given a diet rich in saturated fatty acids and the other group a diet rich in polyunsaturated fatty acids. We have also determined the concentrations of cholesterol and phospholipid in the serums of the animals on the different dietary treatments. 1956).

Differential lectin reactivities of α‐fetoprotein in hepatocellular carcinoma: Diagnostic value when serum α‐fetoprotein levels are slightly raised

The specificity and sensitivity of α‐fetoprotein (AFP) binding to Concanavalin‐A (Con‐A) and Lens culinaris agglutinin (LCA) in 26 South African blacks with advanced symptomatic hepatocellular carcinoma (HCC) but only slightly raised serum AFP concentrations (20–500 ng/mL) was compared with that in patients with similar serum AFP levels from diseases that might be mistaken clinically for HCC (seven ‘benign’ liver disease [BLD] patients and six with metastatic liver disease [MLD] from gastrointestinal tumours). Con‐A–Sepharose‐4B affinity chromatography did not differentiate between the different groups: fucosylation rations for the HCC patients were 0.81 ± 0.60, compared with 0.63 ± 0.27 and 0.54 ± 0.32 in patients with BLD and MLD, respectively. Electrophoresis of AFP serum and fractions in the presence or absence of Con‐A and LCA showed an increase in the AFP C2 band. Rank correlation analysis of the AFP L2 and L3 bands combined could distinguish between patients with HCC and other hepatic diseases (P < 0.05).

Subcellular fractionation of murine erythroleukemic cells : distribution of protein kinases

A method for subcellular fractionation of murine erythroleukemic cells is described; a highly purified cytosol fraction and significantly enriched membrane, mitochondrial, and nuclear fractions were obtained. During development of the procedure, we demonstrated how the composition of the extraction buffers and the techniques used can affect activity and distribution of protein kinases. Protein kinases in the various fractions were separated by nondenaturing electrophoresis and detected by phosphorylation and autoradiography. Differences in the relative proportions of the kinases, which may be significant in relation to differentiation, were seen in all the fractions on hexamethylenebisacetamide treatment of the cells.

Protein kinases associated with proliferation and differentiation in murine erythroleukaemic cells

1. The changes in electrophoretic distribution of cytosolic protein kinases have been studied in relation to proliferation, differentiation and transformation in murine erythroleukaemic cells, using a non-denaturing polyacrylamide gel electrophoresis system. 2. Native molecular masses of the major forms were determined by Ferguson plots. 3. A two dimensional electrophoresis method was developed for determination of the subunit molecular masses. 4. These studies suggest that the major bands of activity contain components which may correspond to cGMP dependent protein kinase, cAMP dependent protein kinase and protein kinase C. 5. On hexamethylene bisacetamide induced differentiation of the cells, changes in proportions of the different forms were observed.

The purification and some properties of 3-hydroxyanthranilate oxygenase from baboon liver

Abstract 1. 1. 3-Hydroxyanthranilic acid oxygenase was purified about 200-fold from baboon liver. 2. 2. The activity of the enzyme is dependent upon Fe2+ and exhibits a pH optimum between pH 7.4–7.6. 3. 3. Final preparations of the enzyme ranged in specific activity from 7 to 8 units/mg of protein. 4. 4. The Km for 3-hydroxyanthranilic acid was 105 μM and KmO2 was 615 μM. 5. 5. By gel filtration and sodium dodeeyl sulphate electrophoresis the enzyme was found to have a molecular weight between 35,000–40,000 daltons. 6. 6. The purified enzyme is unstable and experimental evidence points to the existence of more than one active form of the enzyme. The nature of these forms has not been established to date.