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D Bhatnagar

Publications and source records attributed to D Bhatnagar.

At least 91 records · Page 5Linked to original sources
PubMed1995

Cadmium-induced lipid peroxidation and the status of the antioxidant system in rat tissues.

Cadmium may induce oxidative damage in different tissues by enhancing peroxidation of membrane lipids and altering the antioxidant system of the cells. The peroxidative damage to the cell membrane may cause injury to cellular components due to the interaction of metal ions with the cell organelles. The treatment with Cd (0.4 mg/kg body wt, ip) significantly increased lipid peroxidation (LPO) in heart within 3 h of the Cd injection, while the increase in kidney and liver followed 6 to 12 h after Cd intoxication. The antioxidant enzymes and other antioxidants provide protection to the cells against oxidative damage. The superoxide dismutase (SOD) activity increased in heart, kidney and liver within 24 h of Cd intoxication. The CAT activity increased significantly in heart 9 h after Cd injection; however, no significant change in CAT activity was observed in kidney and liver tissues. The GSH content and the activity of GR decreased in heart, kidney and liver 72 h after Cd administration, which has been suggested to be the cause for increased LPO in the tissues. The hexose monophosphate (HMP) shunt enzymes generate NADPH required for the activity of GR which may affect the GSH content in the tissues. The generalised decrease in glucose 6-phosphate dehydrogenase (G6PDH) and 6 phospho gluconate dehydrogenase (6PGDH) at 9 h followed by an increase in these enzymes in tissues 72 h after Cd intoxication suggest that the production of NADPH by the HMP shunt is required to reduce the oxidative damage. The results show that Cd induced LPO in the tissues and the condition was partially counteracted by the antioxidant system.

Animals↗
PubMed1995

Fetal and maternal lipoprotein metabolism in human pregnancy.

1. Lipid, apolipoprotein concentration and composition were determined in maternal venous and umbilical arterial and venous blood at delivery by elective Caesarean section in 13 full-term pregnancies and in 25 healthy non-pregnant females. The indications of Caesarean section were a previous Caesarean section or breech presentation. None of the women was in labour and there were no other complications of pregnancy or fetal distress. 2. The objectives of the study were to establish whether the placenta has a role in feto-maternal cholesterol metabolism through either synthesis or transplacental cholesterol flux. The potential for free cholesterol diffusion between mother and fetus and rates of cholesterol esterification and transfer between lipoproteins were determined and related to the differences in composition between fetal and maternal lipoproteins. 3. Pregnant women had raised levels of all lipid and lipoprotein fractions compared with control subjects. The greatest increases were in free cholesterol and triacylglycerol (P < 0.0001). Lipoprotein (a) levels were significantly greater in the pregnant women [112 (12.2) mg/l] than in the control women [50 (10.0) mg/l]. 4. The only significant correlation between maternal and fetal lipoprotein concentrations was in lipoprotein (a) levels (r = 0.791, P = 0.002). In both umbilical venous and arterial blood, concentrations of very-low- and low-density lipoproteins, particularly apolipoprotein B, cholesteryl ester and triacylglycerol, were lower than in maternal blood (P < 0.0001), but high-density lipoprotein levels were similar. 5. There was no umbilical arteriovenous differences in lipoprotein concentration or composition. This suggests that cholesterol synthesis or free cholesterol diffusion does not occur in the placenta.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Sequence variability in homologs of the aflatoxin pathway gene aflR distinguishes species in Aspergillus section Flavi.

The Aspergillus parasiticus aflR gene, a gene that may be involved in the regulation of aflatoxin biosynthesis, encodes a putative zinc finger DNA-binding protein. PCR and sequencing were used to examine the presence of aflR homologs in other members of Aspergillus Section Flavi. The predicted amino acid sequences indicated that the same zinc finger domain, CTSCASSKVRCTKEKPACARCIERGLAC, was present in all of the Aspergillus sojae, Aspergillus flavus, and Aspergillus parasiticus isolates examined and in some of the Aspergillus oryzae isolates examined. Unique base substitutions and a specific base deletion were found in the 5' untranslated and zinc finger region; these differences provided distinct fingerprints. A. oryzae and A. flavus had the T-G-A-A-X-C fingerprint, whereas A. parasiticus and A sojae had the C-C-C-C-C-T fingerprint at the corresponding positions. Specific nucleotides at positions -90 (C or T) and -132 (G or A) further distinguished A. flavus from A. oryzae and A. parasiticus from A. sojae, respectively. A sojae ATCC 9362, which was previously designated A. oryzae NRRL 1988, was determined to be a A. sojae strain on the basis of the presence of the characteristic fingerprint, A-C-C-C-C-C-C-T. The DNAs of other members of Aspergillus Section Flavi, such as Aspergillus nomius and Aspergillus tamarii, and some isolates of A. oryzae appeared to exhibit low levels of similarity to the A. parasiticus aflR gene since low amounts of PCR products or no PCR products were obtained when DNAs from these strains were used.

Amino Acid Sequence↗
PubMed1995

stcS, a putative P-450 monooxygenase, is required for the conversion of versicolorin A to sterigmatocystin in Aspergillus nidulans.

Sterigmatocystin (ST) and aflatoxin are carcinogenic end point metabolites derived from the same biochemical pathway, which is found in several Aspergillus spp. Recently, an ST gene cluster, containing approximately 25 distinct genes that are each proposed to function specifically in ST biosynthesis, has been identified in Aspergillus nidulans. Each of these structural genes is named stc (sterigmatocystin) followed by a consecutive letter of the alphabet. We have previously described stcU (formerly verA) as encoding a keto-reductase required for the conversion of versicolorin A to ST. We now describe a second A. nidulans gene, stcS (formerly verB), that is located within 2 kb of stcU in the ST gene cluster. An stcS-disrupted strain of A. nidulans, TSS17, was unable to produce ST and converted ST/aflatoxin precursors to versicolorin A rather than ST, indicating that stcS functions at the same point in the pathway as stcU. Genomic sequence analysis of stcS shows that it encodes a cytochrome P-450 monooxygenase and constitutes a novel P-450 family, CYP59. Assuming that StcU activity mimics that of similar P-450s, it is likely that StcU catalyzes one of the proposed oxidation steps necessary to convert versicolorin A to ST. These results constitute the first genetic proof that the conversion of versicolorin A to ST requires more than one enzymatic activity.

Amino Acid Sequence↗
PubMed1995

Comparative mapping of aflatoxin pathway gene clusters in Aspergillus parasiticus and Aspergillus flavus.

Aflatoxins are toxic and carcinogenic secondary metabolites produced by the fungi Aspergillus flavus and A. parasiticus. Aflatoxins are synthesized by condensation of acetate units; their synthesis is estimated to involve at least 16 different enzymes. In this study we have shown that at least nine genes involved in the aflatoxin biosynthetic pathway are located within a 60-kb DNA fragment. Four of these genes, nor-1, aflR, ver-1, and omtA (previously named omt-1), have been cloned in A. flavus and A. parasiticus. In addition, five other genes, pksA, uvm8, aad, ord-1, and ord-2 have been recently cloned in A. parasiticus. The pksA, aad, and uvm8 genes exhibit sequence homologies to polyketide synthase, aryl-alcohol dehydrogenase, and fatty acid synthase genes, respectively. The cDNA sequences of ord-1 and ord-2 genes, which may be involved in later steps of aflatoxin biosynthesis, have been determined; the ord-1 gene product exhibits homology to cytochrome P-450-type enzymes. By characterizing the overlapping regions of the DNA inserts in different cosmid and lambda DNA clones, we have determined the order of these aflatoxin pathway genes within this 60-kb DNA region to be pksA, nor-1, uvm8, aflR, aad, ver-1, ord-1, ord-2, and omtA in A. parasiticus and nor-1, aflR, ver-1, ord-1, ord-2, and omtA in A. flavus. The order is related to the order in enzymatic steps required for aflatoxin biosynthesis. The physical distances (in kilobase pairs) and the directions of transcription of these genes have been determined for both aflatoxigenic species.

Aflatoxins↗
PubMed1995

Increased expression of Aspergillus parasiticus aflR, encoding a sequence-specific DNA-binding protein, relieves nitrate inhibition of aflatoxin biosynthesis.

The aflR gene from Aspergillus parasiticus and Aspergillus flavus may be involved in the regulation of aflatoxin biosynthesis. The aflR gene product, AFLR, possesses a GAL4-type binuclear zinc finger DNA-binding domain. A transformant, SU1-N3 (pHSP), containing an additional copy of aflR, showed increased transcription of aflR and the aflatoxin pathway structural genes, nor-1, ver-1, and omt-1, when cells were grown in nitrate medium, which normally suppresses aflatoxin production. Electrophoretic mobility shift assays showed that the recombinant protein containing the DNA-binding domain, AFLR1, bound specifically to the palindromic sequence, TTAGGCCTAA, 120 bp upstream of the AFLR translation start site. Expression of aflR thus appears to be autoregulated. Increased expression of aflatoxin biosynthetic genes in the transformant might result from an elevated basal level of AFLR, allowing it to overcome nitrate inhibition and to bind to the aflR promotor region, thereby initiating aflatoxin biosynthesis. Results further suggest that aflR is involved in the regulation of multiple parts of the aflatoxin biosynthetic pathway.

Aflatoxins↗
PubMed1995

Molecular characterization of the afl-1 locus in Aspergillus flavus.

An unusual mutation at the afl-1 locus, affecting aflatoxin biosynthesis in Aspergillus flavus 649, was investigated. The inability of strain 649 to produce aflatoxin was found to be the result of a large (greater than 60 kb) deletion that included a cluster of aflatoxin biosynthesis genes. Diploids formed by parasexual crosses between strain 649 and the aflatoxigenic strain 86 did not produce aflatoxin, indicating the dominant nature of the afl-1 mutation in strain 649. In metabolite feeding experiments, the diploids did not convert three intermediates in the aflatoxin pathway to aflatoxin. Northern (RNA blot) analysis of the diploids grown in medium conducive for aflatoxin production indicated that the aflatoxin pathway genes nor1, ver1, and omt1 were not expressed; however, there was low-level expression of the regulatory gene aflR. Pulsed-field electrophoresis gels indicated a larger (6 Mb) chromosome in strain 649 than the apparently homologous (4.9 Mb) chromosome in strain 86. The larger chromosome in strain 649 suggests that a rearrangement occurred in addition to the deletion. From these data, we proposed that a trans-sensing mechanism in diploids is responsible for the dominant phenotype associated with the afl-1 locus in strain 649. Such a mechanism is known in Drosophila melanogaster but has not been described for fungi.

Aflatoxins↗
PubMed1995

Characterization of a splice-site mutation in the gene for the LDL receptor associated with an unpredictably severe clinical phenotype in English patients with heterozygous FH.

We have identified a substitution of G to A in the first base pair of intron 3 in the LDL receptor gene of an English heterozygous familial hypercholesterolemia (FH) patient. Reverse transcription, amplification, and nucleotide sequencing of the LDL receptor mRNA from mononuclear blood cells showed both the normal mRNA and one that lacked the nucleotides encoded by exon 3, which codes for repeat 2 of the ligand-binding domain. The same mutant allele was identified in 2/200 unrelated FH patients from the London area and 4/77 from Manchester. Immunoblotting of cultured lymphoblasts from the index patient revealed the normal receptor protein and smaller amounts of a receptor protein with electrophoretic mobility consistent with a deletion of the 41 amino acid residues encoded by exon 3. Normal amounts of a similar protein were observed when the mutant cDNA was expressed in heterologous cells; this protein showed reduced binding affinity for LDL but bound apoprotein E-containing lipoproteins normally. Despite these and other observations that repeat 2 of the binding domain is relatively unimportant for receptor function in vitro, carriers of this allele exhibit a severe clinical phenotype, typical of FH. Thus, the relationship between genotype and phenotype in heterozygous FH is not always predictable.

Adult↗
PubMed1995

Effect of treatment with a hydroxymethylglutaryl coenzyme A reductase inhibitor on fasting and postprandial plasma lipoproteins and cholesteryl ester transfer activity in patients with NIDDM.

Patients with non-insulin-dependent diabetes mellitus (NIDDM) have a greater risk of developing coronary heart disease than would be expected from a similar degree of hyperlipidemia in nondiabetic populations. Accelerated transfer of cholesteryl esters (CET) from high-density lipoprotein (HDL) to low-density lipoprotein (LDL) and very-low-density lipoprotein (VLDL), a process that is associated with atherosclerosis, may be a possible explanation for this. CET, plasma lipoprotein concentration, and mass in the fasting and postprandial state have been examined in 31 hyperlipidemic patients with NIDDM before and after 8 weeks of treatment with the hydroxymethylglutaryl (HMG)-coenzyme A (CoA) reductase inhibitor pravastatin in a double-blind, placebo-controlled, parallel group study. Body mass index, glycemic control, and blood pressure remained unaltered during the study period. Compared with placebo, pravastatin decreased fasting serum cholesterol (P < 0.001) and LDL cholesterol (P < 0.002) levels. The high basal CET (34.4 +/- 13.1 nmol.ml-1.h-1) was decreased significantly by pravastatin treatment (27.5 +/- 13.7 nmol.ml-1.h-1, P = 0.013). There was a fall in the total cholesterol, free cholesterol, and phospholipid content of the Sf 0-12, 20-60, and 60-400 lipoproteins (all P = 0.001). Lecithin: cholesterol acyl transferase activity was not altered. The postprandial increase in VLDL cholesterol 5 h after a standardized mixed meal was attenuated after pravastatin treatment (P = 0.011). Inhibition of hepatic cholesterol synthesis with an HMG-CoA reductase inhibitor in hyperlipidemic patients with NIDDM decreased serum cholesterol content of triglyceride-rich lipoprotein, thereby decreasing the transfer of cholesteryl ester from HDL to LDL and VLDL.

Adult↗
PubMed1995

Effect of low-dose cyclosporin on plasma lipoproteins and markers of cholestasis in patients with psoriasis.

The benefits of using cyclosporin in organ transplantation to prevent graft rejection outweigh its potential disadvantages, but with the use of low-dose cyclosporin in relatively healthy individuals, such as those with psoriasis, the risk:benefit ratio is altered. The effects of low-dose cyclosporin (< 5 mg/kg body weight) on liver function and serum lipids and lipoproteins were examined in 40 normolipidaemic, normotensive psoriasis patients with normal renal function. After 3 months of treatment, serum cholesterol and bilirubin concentrations and alkaline phosphatase activity increased significantly (p = 0.001), and glomerular filtration rate (GFR) declined from 107 to 96 ml/min/1.73 m2 (p = 0.05). All these values returned to pretreatment levels 3 months after cessation of cyclosporin. In 15 patients in whom lipoproteins were isolated by ultracentrifugation, there was an increase in plasma low-density lipoprotein (LDL) cholesterol (p = 0.05), but very-low-density lipoprotein cholesterol, high-density lipoprotein (HDL) and HDL2 and HDL3 cholesterol concentrations did not change. The increases in serum bilirubin, alkaline phosphatase activity and LDL cholesterol, seen in individuals with normal baseline liver and renal function, which reverted to baseline following cessation of cyclosporin, suggest that cyclosporin-induced hypercholesterolaemia may be due to either decreased biliary excretion of cholesterol or impaired catabolism of LDL.

Biomarkers↗
PubMed1994

Suppression of non-esterified fatty acids to treat type A insulin resistance syndrome.

A patient with type A insulin-resistance syndrome resistance presented with severe hypertriglyceridaemia and diabetes. Fasting insulin and non-esterified fatty acids (NEFA) were very high (41 mU/L and 3.3 mmol/L). A low-fat diet failed to correct hyperlipidaemia and diabetes. Sustained suppression of NEFA with slow-release acipimox for 8 weeks resulted in substantial reduction of serum fasting NEFA (0.31 mmol/L). Glucose tolerance became normal and insulin sensitivity increased from 7% to 32%. The glucose fatty-acid cycle may operate in patients with severe insulin resistance and hyperlipidaemia: high serum NEFA aggravates insulin resistance and hyperglycaemia by inhibiting glucose uptake and utilisation.

Acanthosis Nigricans↗
PubMed1994

Synthesis of sterigmatocystin on a chemically defined medium by species of Aspergillus and Chaetomium.

Sterigmatocystin (ST) is a secondary metabolite and a principal mycotoxin known to be produced by over 30 species of filamentous fungi. It is also one of the late intermediates in aflatoxin biosynthesis. We have tested the ability of 7 species of Aspergillus, including 4 strains of A. versicolor, one species of Bipolaris, and two species of Chaetomium, to produce ST on a sucrose-salts-phenylalanine defined medium as well as on three complex substrates. Highest ST production in our survey was by a strain of A. versicolor grown on wheat, whereas, the highest ST production on defined medium was by C. cellulolyticum. To our knowledge, this is the first report of ST production by C. cellulolyticum on any substrate. In precursor feeding studies, resting cultures of wild type A. nidulans and A. versicolor were unable to biotransform O-methylsterigmatocystin (OMST), the last known intermediate in aflatoxin biosynthesis. These results suggest that ST is the end product of polyketide metabolism in the strains tested.

Aspergillus↗
PubMed1994

Effects of Neem Leaf Volatiles on Submerged Cultures of Aflatoxigenic Aspergillus parasiticus.

Microbe-free compressed air was passed continuously for a 3-day test period through an enclosed system containing fresh neem leaves; the resultant emitted volatiles were passed over the surface of submerged liquid cultures of a wild-type aflatoxigenic isolate of Aspergillus parasiticus. Aflatoxin determinations for the fungal culture that received neem-derived volatiles, after a 3-day incubation period, resulted in a 90% overall reduction in aflatoxin production and a 51% reduction in fungal biomass when compared with cultures that did not receive neem volatiles. In a separate experiment but in a similarly enclosed system, volatiles from fresh neem leaves were collected on a small Tenax column and were thermally desorbed and cryogenically focused on a capillary gas chromatography column. The neem volatiles were subsequently separated and identified by gas chromatography-mass spectrometry. Sixty-eight compounds were identified by comparison of retention times and mass spectra with either authentic compounds or spectra from a computer-assisted library database of mass spectra. It was found that 10% of the total headspace volatiles were composed of C(3) to C(9) alkenals, which are toxic to aflatoxigenic Aspergillus spp., which could explain the bioactivity that resulted in reduced biomass in the neem-treated cultures.

Journal Article↗
PubMed1994

Variability among atoxigenic Aspergillus flavus strains in ability to prevent aflatoxin contamination and production of aflatoxin biosynthetic pathway enzymes.

Five strains of Aspergillus flavus lacking the ability to produce aflatoxins were examined in greenhouse tests for the ability to prevent a toxigenic strain from contaminating developing cottonseed with aflatoxins. All atoxigenic strains reduced contamination when inoculated into developing bolls 24 h prior to the toxigenic strain. However, only one strain, AF36, was highly effective when inoculated simultaneously with the toxigenic strain. All five strains were able to inhibit aflatoxin production by the toxigenic strain in liquid fermentation. Thus, in vitro activity did not predict the ability of an atoxigenic strain to prevent contamination of developing bolls. Therefore, strain selection for competitive exclusion to prevent aflatoxin contamination should include evaluation of efficacy in developing crops prior to field release. Atoxigenic strains were also characterized by the ability to convert several aflatoxin precursors into aflatoxin B1. Four atoxigenic strains failed to convert any of the aflatoxin biosynthetic precursors to aflatoxins. However, the strain (AF36) most effective in preventing aflatoxin contamination in developing bolls converted all tested precursors into aflatoxin B1, indicating that this strain made enzymes in the aflatoxin biosynthetic pathway.

Aflatoxins↗
PubMed1994

Molecular characterization of aflR, a regulatory locus for aflatoxin biosynthesis.

Aflatoxins belong to a family of decaketides that are produced as secondary metabolites by Aspergillus flavus and A. parasiticus. The aflatoxin biosynthetic pathway involves several enzymatic steps that appear to be regulated by the afl2 gene in A. flavus and the apa2 gene in A. parasiticus. Several lines of evidence indicate that these two genes are homologous. The DNA sequences of the two genes are highly similar, they both are involved in the regulation of aflatoxin biosynthesis, and apa2 can complement the afl2 mutation in A. flavus. Because of these similarities, we propose that these two genes are homologs, and because of the ability of these genes to regulate aflatoxin biosynthesis, we suggest that they be designated aflR. We report here the further characterization of aflR from A. flavus and show that aflR codes for a 2,078-bp transcript with an open reading frame of 1,311 nucleotides that codes for 437 amino acids and a putative protein of 46,679 daltons. Analysis of the predicted amino acid sequence indicated that the polypeptide contains a zinc cluster motif between amino acid positions 29 and 56. This region contains the consensus sequence Cys-Xaa2-Cys-Xaa6-Cys-Xaa6-Cys-Xaa2-Cys-Xaa6+ ++-Cys. This motif has been found in several fungal transcriptional regulatory proteins. DNA hybridization of the aflR gene with genomic digests of seven polyketide-producing fungi revealed similar sequences in three other species related to A. flavus: A. parasiticus, A. oryzae, and A. sojae. Finally, we present evidence for an antisense transcript (aflRas) derived from the opposite strand of aflR, suggesting that the aflR locus involves some form of antisense regulation.

Aflatoxins↗
PubMed1994

Effects of a new fish oil concentrate on plasma lipids and lipoproteins in patients with hypertriglyceridaemia.

OBJECTIVES: The effect of a fish oil preparation, K-85, in which the omega-3 fatty acid content was concentrated to 92% of total fat, on serum lipid and lipoprotein concentrations was investigated in patients with primary hypertriglyceridaemia. DESIGN: The study was a randomized, double-blind, placebo-controlled study. SETTING: Seven centres participated in the study, five secondary referral centres and two general practices. SUBJECTS: Men and women aged 18-70 years with fasting serum triglyceride concentrations between 2 and 10 mmol/l and fasting serum cholesterol concentrations > 5.2 mmol/l were studied. Patients with diabetes mellitus, hypothyroidism, serious illness in the previous 3 months or severe concurrent illness were excluded from the study, as were drug or alcohol abusers and pregnant and lactating women. Ninety-five subjects entered the study, 79 completed the study. INTERVENTIONS: Patients were randomized to receive K-85 2 g twice daily or corn oil 2 g twice daily for 14 weeks. MAIN OUTCOME MEASUREMENTS: The serum concentrations of triglycerides and cholesterol, very low-density lipoprotein (VLDL), low-density lipoprotein (LDL), high-density lipoprotein (HDL) and lipoprotein (a). Fasting blood glucose and blood pressure. RESULTS: Serum triglycerides and VLDL-cholesterol were significantly lower in the group treated with K-85 than in the placebo group after 6, 10 and 14 weeks (all P < 0.01) and there was a decrease in the serum triglyceride concentration from 3.99 (2.94-9.47) to 2.87 (1.2-9.93) mmol/l (P < 0.001) and in VLDL-cholesterol from 1.47 (0.77-3.63) to 1.12 (0.21-3.67) mmol/l (P < 0.01) in patients receiving K-85. Serum HDL-cholesterol increased from 0.98 (0.95-1.01) to 1.11 (1.07-1.15) mmol/l (P < 0.01) in the patients with type IV hyperlipoproteinaemia but did not change in those with type IIb. Serum LDL-cholesterol, lipoprotein (a) and fasting blood glucose were unaffected by K-85. Diastolic blood pressure decreased from 86 +/- 11 to 80 +/- 12 mmHg (P < 0.02) and was also lower than in the placebo group (P < 0.05). The corn oil placebo did not affect any of the parameters. CONCLUSION: K-85 is effective in lowering serum triglycerides and VLDL in patients with primary hypertriglyceridaemia and may have utility as a triglyceride-lowering agent.

Adult↗
PubMed1994

A prospective study of serum lipoproteins after coronary artery bypass surgery.

We examined the acute and long-term effects of coronary artery bypass (CABG) surgery on serum lipid, lipoprotein and apolipoprotein levels. One series of 34 patients having CABG surgery was studied pre-operatively and for six weeks afterwards, and another 22 patients were investigated before and two years after CABG surgery. None of the patients studied received any lipid-lowering drug therapy or specific dietary advice. In both groups, pre-operative serum lipoprotein (a) (Lp(a)) and serum triglyceride concentrations were raised and serum high-density lipoprotein (HDL) cholesterol and apolipoprotein AI (apo AI) were low compared to healthy people. Acutely, there were profound decreases of 40-60% in the serum levels of cholesterol (p < 0.001), low-density lipoprotein cholesterol (p < 0.05), triglycerides (p < 0.01), Lp(a) (p < 0.05) and apolipoprotein B (apo B) (p < 0.05). There was a small decrease in serum apo A1 (p < 0.05), and serum HDL cholesterol showed no change. All these variables regained their pre-operative values within six weeks. Two years postoperatively, serum Lpa was 40% less than its pre-operative concentration (p < 0.001) and HDL cholesterol had increased (p < 0.001). Triglyceride levels decreased (p < 0.02) when beta-blockade was withdrawn. The long-term decrease in Lp(a) following surgery is unlikely to be due either to stopping beta-blockers or to life-style changes. Myocardial ischaemia relieved by the operation may have been partially responsible for its previously raised concentration.

Adult↗