The effect of propionate on lipid synthesis in rat lymphocytes

1. The effect of propionate on lipid synthesis in lymphocytes cultured for 24 hr and incubated for 2 hr was investigated. 2. [1-14C]-propionate was incorporated mainly into phospholipids in both control and concanavalin A (Con A) stimulated cultured lymphocytes. 3. The content of free coenzyme A markedly decreased in 2 hr incubated lymphocytes when propionate was added to the medium at concentrations from 10 to 100 mmol/l. 4. Propionate at 40 mmol/l decreased the incorporation of [1-14C]-palmitate into phospholipids (86%), triacylglycerol (87%) and cholesterol ester (98%) and increased in cholesterol (133%) of cultured lymphocytes. 5. Addition of propionate into the culture medium at 2.5 and 5.0 mmol/l concentrations markedly increased the activity of hydrolases of various acylCoA derivatives. 6. The results suggest that propionate may reduce the content of acylCoA and so its esterification and this might be important for the regulation of lymphocytes proliferation.     

ALL-1 interacts with unr, a protein containing multiple cold shock domains

The ALL-1 gene is involved in human acute leukemia through chromosome translocations and fusion to partner genes, or through partial tandem duplications. ALL-1 is the human homologue of Drosophila trithorax which transregulates the homeotic genes of the Antennapedia and bithorax complexes controlling body segment identity. ALL-1 encodes a very large protein of 3968 amino acids which presumably interacts with many proteins. Here we applied yeast two hybrid screening to identify proteins interacting with the N-terminal segment of ALL-1. One protein obtained in this way was the product of the unr gene. This protein consists of multiple repeats homologous to the cold shock domain (CSD), a motif common to some bacterial and eukaryotic nucleic acids-binding proteins. The minimal region on unr required for the interaction with ALL-1 included two CSD and two intervening polypeptides. The interaction was confirmed by in vitro binding studies, and by coimmunoprecipitation from COS cells overexpressing the relevant segments of the two proteins. These results suggest that unr is involved in an interaction of ALL-1 with DNA or RNA.     

Calcium promotes cell survival through CaM-K kinase activation of the protein-kinase-B pathway

The protection against apoptosis provided by growth factors in several cell lines is due to stimulation of the phosphatidylinositol-3-OH kinase (PI(3)K) pathway, which results in activation of protein kinase B (PKB; also known as c-Akt and Rac) and phosphorylation and sequestration to protein 14-3-3 of the proapoptotic Bcl-2-family member BAD. A modest increase in intracellular Ca2+ concentration also promotes survival of some cultured neurons through a pathway that requires calmodulin but is independent of PI(3)K and the MAP kinases. Here we report that Ca2+/calmodulin-dependent protein kinase kinase (CaM-KK) activates PKB directly, resulting in phosphorylation of BAD on serine residue 136 and the interaction of BAD with protein 14-3-3. Serum withdrawal induced a three- to fourfold increase in cell death of NG108 neuroblastoma cells, and this apoptosis was largely blocked by increasing the intracellular Ca2+ concentration with NMDA (N-methyl-D-aspartate) or KCl or by transfection with constitutively active CaM-KK. The effect of NMDA on cell survival was blocked by transfection with dominant-negative forms of CaM-KK or PKB. These results identify a Ca2+-triggered signalling cascade in which CaM-KK activates PKB, which in turn phosphorylates BAD and protects cells from apoptosis.     

Effect of selective and non-selective muscarinic blockade on baclofen inhibition of gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine in Wistar rats

The effects of baclofen, a gamma-amino-n-butyric acid receptor B agonist, on gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine and how its effects are influenced by selective (M1) and non-selective (M1 and M2) pharmacological blockade of muscarinic receptors were investigated in inbred Wistar rats. Rats were given s.c. injections of 8 mg/kg body wt baclofen with and without 0.5 mg/kg body wt atropine (non-selective M1 and M2 muscarinic receptor antagonist) or 1.0 mg/kg body wt pirenzepine (selective M1 muscarinic receptor antagonist) every other day after a 25 week carcinogen treatment. At week 52 baclofen significantly decreased the incidence of gastric cancers. Concomitant treatment with atropine significantly attenuated the inhibition by baclofen of gastric carcinogenesis, but combined use with pirenzepine had no significant effect on the inhibition by baclofen of gastric carcinogenesis. Baclofen also significantly decreased the labeling index of the antral mucosa. Baclofen plus atropine attenuated the decrease in the labeling index of the antral mucosa due to baclofen, but baclofen plus pirenzepine had no significant effect on the labeling index. These results suggest that the inhibition of gastric carcinogenesis by baclofen is mediated through muscarinic receptors and M2 receptors, but not M1 receptors, are involved in this response.     

Regulation of albumin mRNA and its promoter-binding nuclear factors under different perioperative nutritional methods in hepatectomized rats

BACKGROUND: Regulation of perioperative albumin synthesis under parenteral (PN) and enteral (EN) nutrition was investigated. METHODS: Rats were divided into PN and EN groups. Both groups received the same regimen of artificial nutrition for 7 days and then underwent 70% hepatectomy. Serum albumin and mRNA levels of albumin and its promoter-binding nuclear factors (C/EBPalpha, beta, and DBP) were measured. RESULTS: Serum albumin and albumin mRNA in the PN group were significantly lower than those in the EN group at 72 hours after hepatectomy. Preoperative and postoperative DBP and C/EBPalpha mRNA levels in the EN group were significantly higher than those in the PN group. CONCLUSION: Serum albumin was well maintained by EN after hepatectomy owing to an early recovery of albumin mRNA level and its nuclear factor mRNA levels (C/EBPalpha and DBP). Compared with PN, EN is a more advantageous from of perioperative nutrition as pertains to albumin synthesis.     

A Fully-Automated Electron Beam Test System for VLSI Circuits

A fully automated, stroboscopic electrobeam test system that analyzes the behavior of logic VLSI circuits, this system consists of a stroboscopic electron-beam tester combined with an LSI CAD system. LSI circuit design data, read from the CAD system, provides a designed map. The host computer performs interconnection pattern recognition by superimposing this map onto an observed stroboscopic SEM image. Then, once the circuit nodes for voltage waveform measurements are automatically determined on the superimposed map. Next, the electron beam is positioned on the actual circuit-under-test wires. These automatic processes result in measured waveforms, which are displayed on the host computer terminal. This system has been applied to a 2.3K-gate logic LSI circuits, and has been successful in locating the critical path. This system, coupled with the recently developed fault diagnostic electron-beam tester, Finder, constitutes a unified electron-beam test system.     

Intake of different eicosapentaenoic acid-containing lipids and fatty acid pattern of plasma lipids in the rats

The ethyl ester of eicosapentaenoic acid (EPA) is the only pure EPA-containing lipid available in bulk for oral administration. However, there is doubt as to whether EPA ethyl ester can efficiently increase the plasma levels of EPA in comparison with the ability of other kinds of EPA-containing lipids to do so. Therefore, two other kinds of EPA-containing lipids were prepared to study the efficiency of oral administration of those lipids for increasing the EPA content in plasma phospholipids and cholesteryl esters. EPA-containing lipids which were investigated were [A], 1,2,3-trieicosapentaenoyl-glycerol, [B] 2-eicosapentaenoyl-phosphatidylcholine and [C] ethyl ester of EPA. An adjusted amount of lipids [A], [B] and [C] was administered to rats through a gastric tube for 4 days (the first experiment) or for 10 days (the second experiment), and the fatty acid composition of plasma phospholipids and cholesteryl esters was determined. In the first experiment, there were no significant differences in the efficiency for increasing EPA levels in either phospholipids or cholesteryl esters among the lipids. In the second experiment, the EPA levels of both plasma phospholipids and cholesteryl esters of rats administered ethyl ester of EPA were significantly higher than those of rats administered 2-eicosapentaenoyl-phosphatidylcholine. The EPA levels of the rats administered 1,2,3-trieicosapentaenoylglycerol were between the levels of the two groups mentioned above, but the differences in the EPA levels were not significant. Although an ethyl ester-type molecule is not a naturally occurring lipid, ethyl ester of EPA is equal to 1,2,3-trieicosapentaenoyl-glycerol and appears to be superior to 2-eicosapentaenoyl-phosphatidylcholine as to the efficiency for increasing EPA levels in total plasma phospholipids and plasma cholesteryl esters.     

Apparatus for torsional braid analysis by a digital data analyzer

As apparatus for torsional braid analysis (TBA), which is a variant of the torsional pendulum technique, a new method for recording the damped wave electrically, using an electric mater as a transducer, is described. In order to process a large volume of data, an instrument to print out digitally the amplitude and period of oscillation has been developed. The thermomechanical behavior of poly(vinyl chloride) is presented so as to demonstrate the use of the present TBA apparatus.     

ST-segment elevation in right precordial leads implies depressed right ventricular function after acute inferior myocardial infarction

BACKGROUND: The prognosis of acute inferior myocardial infarction is worse when it is complicated by right ventricular infarction. ST elevation in the right precordial leads is one of the reliable methods for detecting acute right ventricular infarction. The purpose of the study was to examine the relation between ST elevation in the right precordial electrocardiographic leads during acute inferior infarction and the severity of right ventricular systolic dysfunction. METHODS: This study analyzed the relation between ST elevation > or = 0.1 mV in V4R and the severity of right ventricular systolic dysfunction in 43 consecutive patients (men/women: 35/8; average age 62+/-9 years) with acute inferior myocardial infarction with a rapid-response Swan-Ganz catheter to measure the right ventricular ejection fraction (RVEF). RESULTS: RVEF was significantly lower in patients with ST elevation (n = 18) than in those without (n = 25) (33%+/-6% vs 40%+/-9%, p = 0.010). If the infarct-related lesion was located in the proximal right coronary artery, RVEF tended to be lower than if the lesion was located in the distal right coronary artery or the left circumflex coronary artery (33%+/-10% vs 37%+/-9% vs 42%+/-9%, p = 0.101). Logistic regression analysis demonstrated that ST elevation in V4R was the only independent predictor of depressed RVEF (odds ratio = 5.31, 95% confidence interval = 1.28 to 22.1, p = 0.022). CONCLUSION: ST elevation in lead V4R during acute inferior myocardial infarction predicts right ventricular systolic dysfunction.