The OIE PVS tools and expert evaluations: key elements for improving the governance of veterinary services.

The OIE tools for evaluating the Performance of Veterinary Services (OIE PVS tools) were drafted using the same science-based and mutually agreed procedure as for the OIE Terrestrial Animal Health Code. The aim of the PVS tools is to improve Veterinary Services (VS) in accordance with their own specific context by harmonising the fundamental principles of VS quality and the criteria for evaluating it. Experts use the OIE PVS tools to propose ways of improving VS governance in any context. Clearly, the weakest states do not have the capacity to implement structural reforms without the support of development partners, themselves acting in a coordinated and complementary manner on the basis of OIE PVS analyses. Special attention must be paid to four areas of critical competencies for improving VS governance: Veterinary legislation is the subject of an OIE expert evaluation to enable VS to take ownership of the legislative development process, which is manifestly lacking in many countries. Initial education for veterinarians enforces the gradual but clear harmonisation of curricula under the aegis of the OIE, in partnership with relevant authorities. Maintenance or restoration of the VS chain of command must be clearly identified as a priority factor of governance that is vital to VS effectiveness and efficiency. Lastly, although it is based on multiple criteria, technical independence of VS requires sufficient income levels not only to meet the basic needs of staff (both public and private), but also to ensure that they receive recognition and social and professional protection. These elements must be integrated into the functional analysis and can be analysed using the OIE PVS tools.

[The cost in calculating transport noise disturbances in public decision making]. / La prise en compte des nuisances sonores dues aux transports dans les décisions publiques.

The public decision-making methods in transport are based on cost-benefit analysis, by which the consequences of the decision (standards for vehicles, new infrastructures...) are converted in monetary amounts and compared to the cost of implementation of the decision. But some of these consequences, especially those related to environment, are not directly expressed in monetary terms. The article aims at offsetting this difficulty in the case of noise. The possible methods for getting money values of noise are presented; it is shown that the estimates to which they lead are coherent and consistent. Then a comparison is made between the present procedures and the procedures which could be implemented, and it is shown that large gains of efficiency could be obtained.

Effects of 2-(substituted-sulfanyl)-3,5-dihydro-imidazole-4-one and 2-(substituted-sulfanyl)-1H-imidazole-4,5-dione derivatives on serum HDL-cholesterol.

A series of 2-substituted sulfanyl-3,5-dihydro-imidazole-4-ones and 2-substituted sulfanyl-1H-imidazole-4,5-diones was prepared and shown to increase high density lipoprotein cholesterol over other lipid fractions. Compound 1f showed efficacy in additional animal models. The major metabolite of 1f was isolated and its synthesis is reported. The effects of the metabolite on the lipid profile in rats were investigated.

Synthesis and secretion of plasminogen activator inhibitor-1 by human preadipocytes.

To further investigate the role of plasminogen activator inhibitor-1 (PAI-1) in adipose tissue physiology, the production and regulation of PAI-1 was determined in primary cultures of human preadipocytes. When expressed as production per cell and cultured under identical conditions, human preadipocytes from both visceral (omental) and sc depots of lean and obese individuals released significant, yet similar, amounts of PAI-1 protein into the conditioned medium. High steady-state PAI-1 messenger RNA (mRNA) concentrations were observed in visceral and sc preadipocytes, with the relative level of expression equivalent to beta-actin mRNA. Tumor necrosis factor alpha significantly decreased PAI-1 production in a concentration-dependent manner in both visceral and sc cultures, whereas transforming growth factor beta significantly elevated PAI-1 production, but only in sc preadipocytes from obese individuals. Addition of insulin had no effect on antigen levels in conditioned medium of preadipocyte cultures. Stimulation of the preadipocyte cultures with a defined medium resulted in differentiation to the adipocyte phenotype, as determined by flow cytometric analysis, verifying the cultures as human preadipocyte. These studies are the first to observe significant PAI-1 mRNA expression and protein production in primary cultures of a human adipose tissue cellular component, and they suggest that nascent adipocytes contribute significantly to the elevated plasma PAI-1 observed in obesity.

A homogeneous method to quantify mRNA levels: a hybridization of RNase protection and scintillation proximity assay technologies.

A novel method to measure mRNA levels has been developed by combining the detection capabilities of RNase protection (RPA) with the quantification advantages of scintillation proximity assay (SPA) technology. Sample processing is reduced to the addition of a single reagent post RNase digestion. As a model system, the inducible expression of rat apolipoprotein-A1 mRNA has been measured by both traditional gel-based RPAs and the SPA-based RPA assay. Results demonstrate that the ribonuclease protection proximity assay (RiPPA) faithfully reproduces the gel-based results and is at least as sensitive as many existing methods.

Inhibition of the cellular secretion of cholesteryl ester transfer protein by a variant protein formed by alternative splicing of mRNA.

Alternative splicing of mRNA is often used as a regulatory switch, determining whether a functional protein is made or not. The plasma cholesteryl ester transfer protein (CETP) mediates the transfer of cholesteryl esters from high density lipoproteins to other lipoproteins. In addition to the mRNA encoding plasma CETP, human tissues contain an alternatively spliced variant in which exon 9-derived sequences are omitted. To determine a possible regulatory role of alternative splicing, COS cells were co-transfected with full-length and exon 9-deleted cDNAs. The exon 9-deleted protein was poorly secreted and inhibited the secretion of full-length CETP, due to formation of an intracellular heteromeric complex between full-length and exon 9-deleted proteins. The findings suggest a novel use of alternative splicing to generate a poorly secreted protein variant, which complexes with the active form and prevents its secretion by cells.

Adipose tissue cholesteryl ester transfer protein mRNA in response to probucol treatment: cholesterol and species dependence.

Probucol treatment results in an increase in plasma concentrations of cholesteryl ester transfer protein (CETP) which may account, in part, for the effects of this agent on plasma concentrations of HDL cholesterol. We have examined the mechanism by which probucol increases plasma CETP and have determined the associated changes in the plasma distribution of high density lipoprotein (HDL) particles. Studies were carried out in nine hypercholesterolemic subjects and five normal volunteers. Probucol treatment resulted in a 31% increase in plasma concentrations of CETP and a 23% decrease in HDL cholesterol (P < 0.01). The plasma concentration of LpA-I decreased by 40% (P < 0.01) whereas no change occurred in the LpA-I/A-II subclass of HDL. Plasma CETP increased significantly by 1 week of therapy and remained stable over 10 to 14 weeks of therapy. In spite of the significant increase in plasma concentrations of CETP, the abundance of CETP mRNA in peripheral adipose tissue decreased markedly (P < 0.001). These results suggested that probucol may alter CETP synthesis in another tissue such as liver or, alternatively, may have other effects on CETP secretion into or catabolism out of the plasma pool. Further studies were carried out in hamsters because, in this species, adipose tissue is a major site and liver is a negligible site for CETP synthesis. Hamsters were fed probucol with or without dietary cholesterol because this species was previously shown to respond to dietary cholesterol with an increase in adipose tissue mRNA levels and in plasma CETP concentrations, thus providing the opportunity to determine whether probucol would alter these parameters independently of the dietary cholesterol effect.(ABSTRACT TRUNCATED AT 250 WORDS)

Cholesteryl ester transfer protein and high density lipoprotein responses to cholesterol feeding in men: relationship to apolipoprotein E genotype.

The apolipoprotein (apo) E isoform is an important determinant of the plasma lipoprotein distribution of apoE and of the metabolism of apoE-containing lipoproteins. We have determined the effects of apoE genotype on the plasma lipoprotein response to cholesterol feeding in 30 young normal male subjects (5 E3/2, 11 E3/3, 14 E4/3) under rigorously controlled dietary conditions. Two diets, differing only in cholesterol content (low cholesterol (LC): 80 mg cholesterol/1000 kcal and high cholesterol (HC): 320 mg cholesterol/1000 kcal), were compared using a random crossover design. At the end of the HC as compared to the LC period, total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), and HDL2-C increased by an average of 15%, 21%, 7%, and 23%, respectively, for the three genotype groups combined (P < 0.001 for each). The LDL-C response to dietary cholesterol did not differ among the apoE genotypes. However, the increase in HDL-C varied significantly according to the apoE genotype (E3/2: 0 change, E3/3: +4%, E4/3: +12%; P < 0.05). The plasma cholesteryl ester transfer protein (CETP) response to cholesterol feeding also differed amongst the three apoE genotype groups (E3/2: +37%, E3/3: +18%, E4/3: +9%) (P < 0.05). ApoE genotype has significant and opposite effects on plasma CETP and HDL-C responses to dietary cholesterol in men.

Alternative splicing of the mRNA encoding the human cholesteryl ester transfer protein.

The plasma cholesteryl ester transfer protein (CETP) is known to facilitate the transfer of lipids between plasma lipoproteins. The human CETP gene is a complex locus encompassing 16 exons. The CETP mRNA is found in liver and small intestine as well as in a variety of peripheral tissues. While the CETP cDNA from human adipose tissue was being cloned, a variant CETP cDNA was discovered which excluded the complete sequence encoded by exon 9, but which was otherwise identical to the full-length CETP cDNA, suggesting modification of the CETP gene transcript by an alternative RNA splicing mechanism. RNase protection analysis of tissue RNA confirmed the presence of exon 9 deleted transcripts and showed that they represented a variable proportion of the total CETP mRNA in various human tissues including adipose tissue (25%), liver (33%), and spleen (46%). Transient expression of the exon 9 deleted cDNA in COS cells or stable expression in CHO cells showed that the protein encoded by the alternatively spliced transcript was inactive in neutral lipid transfer, smaller, and poorly secreted compared to the protein derived from the full-length cDNA. Endo H digestion suggested that the inactive, cell-associated protein was present within the endoplasmic reticulum. The experiments show that the expression of the human CETP gene is modified by alternative splicing of the ninth exon, in a tissue-specific fashion. The function of alternative splicing is unknown but could serve to produce a protein with a function other than plasma neutral lipid transfer, or as an on-off switch to regulate the local concentration of biologically active protein.

Plasma lipid transfer protein as a determinant of the atherogenicity of monkey plasma lipoproteins.

This study was undertaken to determine potential tissue sources of plasma cholesteryl ester transfer protein (CETP), and to assess the influence of CETP on lipoprotein concentrations and atherosclerosis. In a group of 28 cynomolgus monkeys fed high fat, high cholesterol diets, plasma CETP concentration was strongly correlated with the abundance of CETP mRNA in liver and in adipose tissue, and with the output of CETP in liver perfusates. Plasma CETP concentration showed a strong inverse correlation with HDL cholesterol concentrations (r = -0.62, P less than 0.001) and a positive correlation with LDL cholesterol concentration (r = 0.54, P less than 0.005) and molecular weight (r = 0.57, P less than 0.001). The extent of coronary artery atherosclerosis was positively correlated with LDL cholesterol concentration and molecular weight, and with plasma CETP concentration. Thus, in monkeys fed an atherogenic diet, individual variation in CETP mRNA abundance in liver and adipose tissue probably plays a major role in the determination of plasma CETP levels. In plasma, CETP influences the distribution of cholesteryl esters between LDL and HDL, and CETP concentration appears to be a key determinant of the relative atherogenicity of the plasma lipoproteins.

Mammalian adipose tissue and muscle are major sources of lipid transfer protein mRNA.

The plasma cholesteryl ester transfer protein (CETP) catalyzes the transfer of cholesteryl esters from high density lipoproteins (HDL) to triglyceride-rich lipoproteins and plays a major role in the catabolism of HDL. Lipoprotein lipase (LPL) is the rate-limiting enzyme for hydrolysis of circulating triglyceride and is involved in HDL formation. We show that tissues containing LPL are major sources of CETP mRNA in several mammalian species, including some with low cholesteryl ester transfer activity in plasma. In hamsters, adipose tissue and heart were found to be the richest sources of both CETP and LPL mRNA; in situ hybridization studies showed that the same cell types (i.e. adipocytes or myocytes) contained CETP and LPL mRNA in these tissues. Isolated adipocytes synthesized active CETP. Dietary studies revealed a complex pattern of response of CETP mRNA levels in different tissues, which showed partial similarity to the changes in LPL mRNA abundance. However, high cholesterol diets resulted in increased CETP mRNA abundance in adipose tissue, heart, and skeletal muscle, without equivalent changes in LPL mRNA. Plasma HDL cholesteryl ester levels showed strong inverse correlations with CETP mRNA abundance in adipose tissue. The results suggest a conserved function of CETP in adipose tissue and heart, such as a co-ordinate action with LPL to enhance HDL turnover. Although there is considerable overlap in the tissue- and cell-specific pattern of CETP and LPL gene expression, dietary studies revealed only limited parallelism in response at the mRNA level. The increase in CETP mRNA in peripheral tissues in response to increased dietary cholesterol suggests that local induction of CETP synthesis may help to recycle cholesterol deposited in these tissues during lipolysis of dietary lipoproteins.

Organization of the human cholesteryl ester transfer protein gene.

The plasma cholesteryl ester transfer protein (CETP) catalyzes the transfer of phospholipids and neutral lipids between the lipoproteins. Thus, this protein may be important in modulating lipoprotein levels in the plasma. We have determined the primary structure and organization of the human CETP gene. Southern blotting of cellular DNA indicated a single copy of the CETP gene exists per haploid genome. Analysis of three overlapping genomic clones showed that the gene spans approximately 25 kbp and contains 16 exons (size range 32-250 bp). Overall, the sequence and organization of the CETP gene do not resemble those of other lipid-metabolizing enzymes or apolipoproteins. However, comparison of the CETP sequence, one exon at a time, with the sequences in the sequence databases revealed a striking identity of a pentapeptide sequence (ValLeuThrLeuAla) within the hydrophobic core of the signal sequences of human CETP, apolipoproteins A-IV and A-I, and lipoprotein lipase. This pentapeptide sequence was not found in the signal sequences of other proteins, suggesting that it may mediate a specialized function related to lipid metabolism or transport.

Atherogenic diet increases cholesteryl ester transfer protein messenger RNA levels in rabbit liver.

Cholesteryl ester transfer activity is increased in plasma of cholesterol-fed rabbits. To investigate the mechanisms leading to changes in activity, we measured cholesteryl ester transfer protein (CETP) mass by RIA and CETP mRNA abundance by Northern and slot blot analysis using a human CETP cDNA probe in control (n = 8) and cholesterol-fed rabbits (n = 10). Cholesterol feeding (chow plus 0.5% cholesterol, 10% corn oil) for 30 d increased CETP mass in plasma 3.2-fold in the cholesterol-fed rabbits (12.45 +/- 0.82 micrograms/ml) compared with controls (3.86 +/- 0.38 micrograms/ml). In the hypercholesterolemic rabbit, liver CETP mRNA levels were increased 2.8 times control mRNA levels. Actin, apo E, lecithin-cholesterol acyltransferase, and albumin mRNA abundances were unchanged. In contrast to the widespread tissue distribution in humans, CETP mRNA was not detected in extrahepatic tissues of either control or cholesterol-fed animals. Using a sensitive RNase protection assay, the increase in liver CETP mRNA was detectable within 3 d of beginning the high cholesterol diet. Thus, in response to the atherogenic diet there is an early increase in liver CETP mRNA, probably causing increased CETP synthesis and secretion, and increased plasma CETP. The results indicate that the CETP gene may be regulated by diet-induced changes in lipid metabolism.

Mechanism of cholesteryl ester transfer protein inhibition by a neutralizing monoclonal antibody and mapping of the monoclonal antibody epitope.

The plasma cholesteryl ester transfer protein (CETP, Mr 74,000) has a binding site for neutral lipid which can readily equilibrate with lipoprotein cholesteryl esters or triglycerides. Recently, a monoclonal antibody (TP2) was obtained which neutralizes the cholesteryl ester (CE) and triglyceride (TG) transfer activities of the CETP. In this report, the epitope of the inhibitory monoclonal antibody has been localized to a hydrophobic 26-amino acid sequence at the COOH terminus of CETP. The Fab fragments of TP2 caused partial (50%) inhibition of CE transfer and complete inhibition of TG transfer by the CETP. Similarly, the Fab fragments inhibited (37%) the binding of CE to the CETP and abolished the binding of TG to the CETP. Surprisingly, the TP2 Fab was also found to enhance the binding of CETP to plasma lipoproteins and to phospholipid vesicles. In conclusion, the TP2 monoclonal antibody inhibits lipid transfer by blocking the uptake of lipid by CETP. The COOH-terminal epitope may be in or near the neutral lipid binding site. Occupancy of this site by TP2 Fab fragments or by neutral lipid may result in a conformational change of CETP causing enhanced binding to lipoproteins or vesicles.

Application of SDS gradient polyacrylamide slab gel electrophoresis to analysis of apolipoprotein mass and radioactivity of rat lipoproteins.

An application of SDS gradient polyacrylamide slab gel electrophoresis to the analysis of lipoprotein polypeptides is described. The 10-15% polyacrylamide gradient provides a high degree of resolution and sensitivity resulting in a single separation of the major apoproteins which can be easily visualized. When combined with autofluorography, individual protein mass and radioactivity can be determined densitometrically while still retaining excellent resolution. Examples of rat lymph and plasma apolipoproteins are shown, and apparent heterogeneity of certain apoprotein subgroups is described.

Apolipoprotein localization and quantitation in the human intestine.

Apolipoproteins B, A-I, and A-IV were localized in human intestinal epithelium using immunoperoxidase techniques. Staining was most obvious in villus tip cells. Lipid absorption resulted in an increase in intraepithelial staining for each apoprotein. The pattern for apo-B in the biopsy specimens taken after lipid absorption revealed a marked redistribution of staining to the intercellular spaces and an increase in the supranuclear staining of apo-A-I and apo-A-IV. After lipid absorption, staining appeared to extend further down the villus than in the fasting biopsy specimens. Quantitation of apo-A-I and apo-A-IV in isolated epithelial cells confirmed that the mass of these apoproteins increases in response to lipid absorption. Apolipoprotein B and apo-A-I were absent in the epithelium of 3 patients with abetalipoproteinemia while apo-A-IV was present in 2 patients. These studies demonstrate differences in the localization and quantitation of apoproteins in the villus-crypt unit as well as differences in the localization pattern of the different apoproteins.

Human apolipoprotein A-IV. Intestinal origin and distribution in plasma.

The role of the human intestine has been explored as a site of synthesis of apoA-IV, a major apoprotein of human intestinal triglyceride-rich lipoproteins. Intestinal biopsies were performed on normal volunteers while fasting and after lipid ingestion. Indirect immunofluorescence demonstrated a marked increase in immunofluorescence for apoA-IV during lipid absorption consistent with an increased intracellular content. ApoA-IV comprised 10-13% of chylomicron apoprotein and 24-30% of intestinal very low density lipoprotein (VLDL) as assessed by densitometry of sodium dodecyl sulfate gels of lipoproteins from chylous urine (mesenteric lymphatic-urinary fistula) and thoracic duct lymph (postoperative fistula). After one subject with chyluria ingested 40 g of corn oil, triglyceride excretion in urine was accompanied by an increased excretion of apoA-IV. 11.5 g of triglyceride and 81 mg of apoA-IV were recovered in the urine. In chylous urine 56% of apoA-IV was in the triglyceride-rich lipoproteins (chylomicrons and intestinal VLDL) and 44% in the d > 1.006-g/ml fraction. Normal plasma apoA-IV was 15.7+/-0.9 mg/dl (n = 14) whereas four subjects with abetalipoproteinemia had reduced levels 1.2, 7.6, 9.6, and 8.3 mg/dl, respectively. Lipid feeding in normal volunteers resulted in a rise in plasma apoA-IV (16.1+/-0.7 mg/dl to 18.5+/-0.7 mg/dl, n = 5, P < 0.01). In fasting plasma, 98% of apoA-IV was in the d > 1.21-g/ml fraction. In lipemic plasma, 10% of apoA-IV was associated with triglyceride-rich lipoproteins and 90% with the d > 1.21-g/ml fraction. Agarose column chromatography of fasting plasma confirmed that the bulk of plasma apoA-IV is free, unassociated with lipoproteins. These results demonstrate that apoA-IV is present in human intestinal epithelial cells and is secreted as a chylomicron and VLDL apoprotein. Within fasting plasma most of the apoA-IV is found free, unassociated with lipoproteins. After lipid ingestion apoA-IV is also found in plasma chylomicrons indicating that some apoA-IV remains associated with chylomicrons in plasma during chylomicron metabolism, although some may be transferred from the chylomicron surface.