Cytolysis of tumor necrosis factor (TNF)-resistant tumor targets. Differential cytotoxicity of monocytes activated by the interferons, IL-2, and TNF

Herein we demonstrate that IFN-alpha, IFN-gamma, and IL-2 can induce human peripheral blood monocyte-mediated lysis of tumor cells that are resistant to both the direct effects of TNF and to monocytes activated by TNF. Monocytes activated by TNF kill only TNF-sensitive tumor targets, whereas those activated by IFN and IL-2 can lyse both TNF-sensitive and TNF-resistant tumor targets. Monocyte cytotoxicity against TNF-sensitive lines induced by the IFN, IL-2, or TNF can be completely abrogated by the addition of anti-TNF antibodies. In contrast, anti-TNF antibodies have no effect on IFN- or IL-2-induced monocyte cytotoxicity against TNF resistant targets, confirming non-TNF-mediated lysis induced by lymphokine-activated monocytes. Neither induction of TNF receptors by IFN-gamma nor inhibition of RNA synthesis by actinomycin D increased the susceptibility of TNF-resistant tumor targets to TNF-mediated monocyte cytotoxicity. Thus, non-TNF-mediated modes of monocyte cytotoxicity are induced by IFN and IL-2, but not by TNF, indicating that different cytotoxic mechanisms are responsible for the lysis of TNF-sensitive and TNF-resistant tumor cells. In addition, these findings also suggest that TNF-sensitive lines are susceptible only to TNF-mediated killing and apparently insensitive to non-TNF-mediated monocyte cytotoxicity.     

Evaluation of eight and a half years of neonatal screening for haemoglobinopathies in Birmingham

A pilot neonatal screening programme for haemoglobinopathies linked with screening for phenylketonuria and congenital hypothyroidism was reviewed. During 1978 to December 1986 137 000 neonates were tested. There were improvements in the detection rate and accuracy of diagnosis for homozygotes and mixed heterozygotes, mainly associated with the introduction of citrate agarose gel electrophoresis as a follow up procedure on all specimens showing any abnormality on the initial cellulose acetate electrophoresis.We recommend that the programme is continued on a service basis.     

A program for drawing evolutionary trees

From the measures of evolutionary distance between pairs ofsequences in a set, it is possible to infer the genetic treeor trees which best fit these known data. DENDRON is a new program,written in FORTRAN 66, which computes an initial tree from thebottom-up, then searches among increasingly divergent treesfor a better fit. As a check on the consistency of the measures,the program tests all triplets for the triangle inequality.DENDRON also calculates a single ‘top-down’ tree,progressing from the trunk to the twigs, for comparison withthe ‘bottom-up’ trees. Received on August 17, 1987; accepted on June 1, 1988     

Instituting a research ethic: chilling and cautionary tales

The ethical review of research on human beings, and indeed the ethical review of broader ranges of human activity, is a growth industry. I want to look here at the ethical review of research on humans and raise some questions about the direction it is taking. I am pessimistic about where the institutions that we have set up are leading us and I want to sound a warning note and suggest some changes that are needed in the practice of ethical review.     

Purification of the Lewis blood-group gene associated α-3/4-fucosyltransferase from human milk: an enzyme transferring fucose primarily to Type 1 and lactose-based oligosaccharide chains

A soluble Lewis blood-group gene associated -3/4-L-fucosyltransferase has been purified from human milk by a series of steps involving hydrophobic chromatography on Phenyl Sepharose 4B, ion exchange chromatography on CM-Sephadex C-50, affinity chromatography on GDP-hexanolamine Sepharose 4B and gel filtration on Sephacryl S-200. The first step separated -3-L-fucosyltransferase activity directed towardsN-acetylglucosamine in Type 2 (Gal1-4GlcNAc-R) acceptors from an -3/4-fucosyltransferase fraction acting on both Type 1 (Gal1-3GlcNAc-R) and Type 2 acceptors. Further purification of this latter fraction on CM-Sephadex and GDP-hexanolamine Sepharose gave a single peak of fucosyltransferase activity that catalysed the addition of fucose toN-acetylglucosamine in both Type 1 and Type 2 acceptors and to theO-3 position of glucose in lactose-based oligosaccharides. The enzyme preparation at this stage resembled previously described -3/4-fucosyltransferase preparations purified from human milk. However, gel filtration of this preparation on Sephacryl S-200 or Sephadex G-150 separated further amounts of -3-fucosyltransferase activity acting solely on Type 2 acceptors and left a residual -3/4-fucosyltransferase that retained strong -4 activity with the Type 1 acceptor, lacto-N-biose 1, and -3 activity with 2-fucosyllactose, but had relatively little -3 activity withN-acetyllactosamine and virtually no capacity to transfer fucose to glycoproteins withN-linked oligosaccharide chains having unsubstituted terminal Type 2 structures.     

Effects of exercise training and diabetes on cardiac myosin heavy chain composition

This study determined whether the beneficial effects of exercise training on the diabetic heart previously observed are associated with alterations in ventricular myosin heavy chain (MHC) isoform composition. Diabetes was induced in rats by i.v. streptozotocin. Trained rats were run on a treadmill for 60 min/day, 27 m/min, 10% grade. After 10 wks, ventricular MHC isoenzyme protein composition was analyzed for MHC composition using gel electrophoresis. -MHC and -MHC mRNA were determined by Northern and slot blot hybridization techniques. Both protein and mRNA analyses indicated that sedentary control rats exhibited a predominance of -MHC. Sedentary diabetics exhibited a shift to -MHC. Exercise trained diabetic rats showed a predominance of -MHC. The results indicate that treadmill exercise training of diabetic rat does not prevent the diabetes-induced shift in MHC composition towards the -MHC isoform, thus it is unlikely that the beneficial effects of exercise training on the diabetic heart, previously shown, are due to a normalization of the myosin isoform composition.     

Oxidation of exogenous carbohydrate during prolonged exercise: the effects of the carbohydrate type and its concentration.

We studied rates of exogenous carbohydrate (CHO) oxidation during 90 min of cycling exercise in trained cyclists exercising at 70% of maximal oxygen consumption (VO2max) when they ingested glucose, sucrose, or glucose polymer solutions at concentrations of 7.5%, 10% or 15%. Drinks were labelled with [U-14C]glucose or sucrose and were ingested at a rate of 100 ml.10 min-1. Rates of oxidation of the ingested CHO were calculated from the specific radio-activity of the labelled CHO, expired 14CO2 and carbon dioxide output (VCO2). Total CHO oxidation, determined from oxygen consumption and VCO2 was not influenced by CHO type or concentration. Gastric emptying (P = 0.01) and the rate of exogenous CHO oxidation (P = 0.028) was greatest for the glucose polymer solutions, and least for glucose. Although gastric emptying (P = 0.006) decreased with increasing CHO concentration, CHO delivery to the intestine and exogenous CHO oxidation increased linearly with increasing CHO concentration. The percentage of the CHO delivered to the intestine that was oxidized ranged from 30.0% for 7.5% CHO to 38.1% for 15% CHO. Our results indicated that the rate of gastric emptying for CHO was not controlled to provide a constant rate of energy delivery as is commonly believed and that factors subsequent to gastric emptying limit the rate of exogenous CHO oxidation from the ingested solution.     

Anaerobic degradation of trans-cinnamate and ω-phenylalkane carboxylic acids by the photosynthetic bacterium Rhodopseudomonas palustris: evidence for a β-oxidation mechanism

The mechanism responsible for the initial steps in the anaerobic degradation of trans-cinnamate and -phenylalkane carboxylates by the purple non-sulphur photosynthetic bacterium Rhodopseudomonas palustris was investigated. Phenylacetate did not support growth and there was a marked CO₂ dependence for growth on acids with greater side-chain lengths. Here, CO₂ was presumably acting as a redox sink for the disposal of excess reducing equivalents. Growth on benzoate did not require the addition of exogenous CO₂. Aromatic acids with an odd number of side-chain carbon atoms (3-phenylpropionate, 5-phenylvalerate, 7-phenylheptanoate) gave greater apparent molar growth yields than those with an even number of side-chain carbon atoms (4-phenylbutyrate, 6-phenylhexanoate, 8-phenyloctanoate). HPLC analysis revealed that phenylacetate accumulated and persisted in the culture medium during growth on these latter compounds. Cinnamate and benzoate transiently accumulated in the culture medium during growth on 3-phenylpropionate, and benzoate alone accumulated transiently during the course of trans-cinnamate degradation. The transient accumulation of 4-phenyl-2-butenoic acid occurred during growth on 4-phenylbutyrate, and phenylacetate accumulated to a 1:1 molar stoichiometry with the initial 4-phenylbutyrate concentration. It is proposed that the initial steps in the anaerobic degradation of trans-cinnamate and the group of acids from 3-phenylpropionate to 8-phenyloctanoate involves -oxidation of the side-chain.Abbreviation 3-PP 3-phenylpropionic acid - 4-PB 4-phenylbutyric acid - 5-PV 5-phenylvaleric acid - 6-PH 6-phenylhexanoic acid - 7-PH 7-phenylheptanoic acid - 8-PO 8-phenyloctanoic acid - 4-P2B 4-phenyl-2-butenoic acid - GC/MS Gas chromatography/Mass spectrometry - HPLC High-pressure liquid chromatography     

Atomic force microscopy examination of the topography of a hydrated bacterial biofilm on a copper surface

A bacterium, designated CCI#8, that was isolated from a corroded copper coupon colonized both polished and unpolished copper surfaces under batch culture conditions. Atomic Force Microscopy (AFM) images revealed that the biofilm was heterogeneous in nature, both in depth and in cell distribution. Bacterial cells were shown to be associated with pits on the surface of the unpolished copper coupons. These observations support previous studies that CCI#8 is associated with the pitting corrosion of copper.     

A nomenclature for the genes encoding the chlorophylla/b-binding proteins of higher plants

We propose a nomenclature for the genes encoding the chlorophylla/b-binding proteins of the light-harvesting complexes of photosystem I and II. The genes encoding LHC I and LHC II polypeptides are namedLhca1 throughLhca4 andLhcb1 throughLhcb6, respectively. The proposal follows the general format recommended by the Commision on Plant Gene Nomenclature. We also present a table for the conversion of old gene names to the new nomenclature.