Pentraxin 3 as a novel diagnostic marker in neonatal sepsis

BACKGROUND

Neonatal sepsis is an important cause of morbidity and mortality especially in developing countries. As clinical manifestations of neonatal sepsis are nonspecific, early diagnosis and treatment remain a challenge. Pentraxin 3 (PTX3) is an acute-phase protein secreted by various cells in response to the proinflammatory signals. Our aim was to investigate the diagnostic value of PTX3 in neonatal sepsis.

METHODS

We studied 90 neonates; 60 with culture-proven sepsis and 30 healthy neonates as a control group. Serum levels of PTX 3 were measured by ELISA.

RESULTS

Neonates with sepsis had significantly higher levels of PTX 3 as compared to controls (p < 0.001). Diagnostic cutoff value of PTX 3 was 5.6 μg/L with a sensitivity of 98.3% and a specificity of 96.7%. PTX 3 was significantly increased in nonsurvivors when compared to survivors (p < 0.001). PTX3 had better sensitivity when compared with CRP.

CONCLUSION

PTX 3 could be used as a new biomarker of neonatal sepsis with high sensitivity and specificity.

Prognostic significance of serum progranulin level in de novo adult acute lymphoblastic leukemia patients

Increased expression of progranulin (PGRN) has been reported in some hematological cancers, but limited information regarding its significance in acute lymphoblastic leukemia (ALL) is available. This study involved 60 subjects (40 de novo adult ALL patients and 20 controls). Serum PGRN level was measured by enzyme-linked immunosorbent assay and was correlated with patient outcome. Serum PGRN level was significantly higher in patients than controls. Serum PGRN level did not correlate with age, total leukocytic count, hemoglobin, platelets, absolute blast count in peripheral blood, lactate dehydrogenase, percent of blasts in bone marrow, gender, comorbidities, the presence of central nervous system infiltration, ALL phenotype, cytogenetics and risk of the disease. High serum PGRN level was not associated with inferior overall survival (OS) on univariate analysis. Regarding cumulative incidence of relapse (CIR) and disease-free survival (DFS), high PGRN level was associated with poor results on univariate analysis. Moreover, it tended to be independent risk factor on multivariate analysis for CIR but was not an independent predictor of inferior DFS. Serum PGRN level is significantly elevated in de novo adult ALL patients and may be used as a predictor of increased relapse risk.

L-carnitine prevents the progression of atherosclerotic lesions in hypercholesterolaemic rabbits

This study has been initiated to investigate, in hypercholesterolaemic rabbits, whether L-carnitine deficiency could be an additional risk factor in atherosclerosis, and if so, whether L-carnitine supplementation could prevent the progression of atherosclerosis. Hypercholesterolaemia was induced by feeding rabbits 2% cholesterol-enriched diet for 28 days, whereas, carnitine deficiency was induced by daily i.p. administration of 250 mg kg(-1) of D-carnitine for 28 days. Histopathological examination of aorta and coronaries from hypercholesterolaemic rabbits revealed severe atherosclerotic lesions, intimal plaques and foam cell formation. Also, hypercholesterolaemic diet resulted in a significant 53 and 43% decrease in reduced glutathion (GSH) levels and a significant (1.87-fold) and (14.1-fold) increase in malonedialdhyde (MDA) levels in aorta and cardiac tissues, respectively. Daily administration of L-carnitine (250 mg kg(-1)) for 28 days, completely prevented the progression of atherosclerotic lesions induced by hpercholesterolaemia in both aorta and coronaries. Conversely, daily administration of D-carnitine (250 mg kg(-1)) for 28 days increased the progression of atherosclerotic lesions with the appearance of foam cells and apparent intimal plaques which are even larger than that seen in hypercholesterolaemic rabbits. Both L-carnitine and D-carnitine produced similar effects on the lipid profile, GSH and MDA which may point to the conclusion that: (1) L-carnitine prevents the progression of atherosclerotic lesions by another mechanism in addition to its antioxidant and lipid-lowering effects; (2) endogenous carnitine depletion and/or carnitine deficiency should be viewed as an additional risk factor in atherogenesis.

Idiotypic regulation in Schistosomiasis mansoni

The role of anti-idiotype Ab2 in regulation of the immune response in schistosomiasis was studied. Positive Ab2 could be detected among the newborns of infected mothers and experimentally S. mansoni- infected mice. Negative anti-idiotypic antibodies were observed among children above 3 years and control mice. Increasing levels of anti-idiotypic antibodies were detected among S. mansoni infected children and adults. Higher mean anti-idiotype A2 levels were found among patients with hepatosplenomegaly than those with intestinal manifestations. The kinetics of anti-idiotype Ab2 among the S. mansoni- infected mice started from the end of the first week after infection up to 8 weeks. It was continuous, but with undulating levels. Moreover, the anti-idiotype antibody was able to stimulate lymphocyte proliferation at 8 weeks post infection.

Adipose monoacylglycerol:acyl-coenzyme A acyltransferase activity in the white-throated sparrow (Zonotrichia albicollis): characterization and function in a migratory bird

Although migrating birds use stored triacylglycerol as their primary fuel for flight, they must retain sufficient stores of omega 6 and omega 3 fatty acids to sustain reproduction after the spring migration. Hepatic monoacylglycerol:acyl-coenzyme A acyltransferase (EC 2.3.1.22) (MGAT) activity is associated with physiological periods in which lipolysis and beta-oxidation are prominent, and it may also play a role in the selective retention of certain essential fatty acids. Therefore, we characterized MGAT activity in adipose tissue from the white-throated sparrow (Zonotrichia albicollis), a migratory bird. MGAT specific activity from adipose tissue and liver, respectively, was 22.2 +/- 7.27 and 0.79 +/- 0.35 nmol/min/mg of total particulate protein. Activity did not vary seasonally or between male and female birds. Specific activity increased 4.3-fold in the presence of 75 micrograms of phosphatidylcholine and phosphatidylserine (1:1, w/w). MGAT acylated sn-1(3)-monooleoylglycerol, sn-2-monooleylglycerol ether and sn-1(3)-monooleylglycerol ether at 7.5, 5.7 and 1.7%, respectively, of the rate observed with sn-2-monooleoylglycerol. An initial lag phase observed at low concentrations of palmitoyl-CoA was corrected by adding 2 mM MgCl2, Mg(NO3)2 or CaCl2, suggesting a requirement for divalent cations. MGAT acylated sn-2-monolinolenoylglycerol and sn-2-monolinoleoylglycerol in preference to sn-2-monooleoylglycerol. Specificity of MGAT for sn-2-monoacylglycerols and the probable enhanced affinity fo sn-2-monoacylglycerols of specific acyl chains may allow selected omega 6 and omega 3 fatty acids to be retained within the adipocyte, while nonessential fatty acids are released for beta-oxidation in flight muscles.

Increased hepatic monoacylglycerol acyltransferase activity in streptozotocin-induced diabetes: characterization and comparison with activities from adult and neonatal rat liver

Hepatic monoacylglycerol acyltransferase (EC 2.3.1.22) (MGAT) is a developmentally-expressed activity associated with physiological periods characterized by high rates of lipolysis and dependence on fatty acids for energy production. During these periods, MGAT may help to retain essential fatty acids selectively. In streptozotocin-diabetes, mean MGAT-specific activity increased 11.8-fold. We characterized microsomal MGAT activity from diabetic and control adult rats, and compared these adult activities with the high neonatal activity. Compared with the activity in neonatal liver, adult MGAT activity was more thermolabile, had a markedly different pH profile, and responded differently to incubation with bovine serum albumin, phospholipids, and MnCl2. Adult diabetic MGAT activity was also stimulated 2-fold by albumin and was markedly thermolabile, but was not inhibited by phospholipid. Diabetic MGAT activity had some properties that combined characteristics observed in adult and neonatal microsomes: a pH dependence that was optimal at pH 7.0 but that plateaued between pH 7.0 and 9.5, and neither stimulation nor inhibition after incubation with MnCl2. Diabetic MGAT acylated monoalkylglycerols more readily than did either the neonatal or the adult MGAT activities. The enhanced expression of hepatic MGAT activity in diabetes is consistent with its postulated role in retaining essential fatty acids during lipolysis.

Selective retention of essential fatty acids: the role of hepatic monoacylglycerol acyltransferase

In the suckling rat, chick embryo, and hibernating marmot, fatty acids provide the major source of energy, and despite the high rate of hepatic beta-oxidation, these animals selectively retain long-chain polyunsaturated derivatives of C18:2n-6 and C18:3n-3. To determine whether the hepatic microsomal activity monoacylglycerol acyltransferase (MGAT) (EC 2.3.1.22) could provide a mechanism to selectively acylate monoacylglycerols that contain essential fatty acids, we tested the ability of MGAT activity from each of the three species to acylate sn-2-monoC18:1-, sn-2-monoC18:2-, sn-2-monoC18:3-, and sn-2-monoC20:4-glycerols. Hepatic MGAT activity acylated sn-2-monoC18:3-glycerol and sn-2-monoC18:2-glycerol in preference to sn-2-monoC18:1-glycerol in each of the three different lipolytic animals. MGAT's acyl group specificity could not be explained by invoking differences in membrane fluidity because the apparent affinity for sn-2-monoC20:4-glycerol was not increased. Further, sn-2-monoC18:3-glycerol remained a preferred substrate under assay conditions when both the C18:3 and C18:1 species were present in equal amounts. As would be predicted in the presence of high activity of a selective MGAT, the hepatic glycerolipids from neonatal rats showed increases in dienoic, trienoic, and C22:6 fatty acids and relative decreases in monoenoic, saturated, and C20:4 fatty acids. We hypothesize that, during lipolysis, the reacylation of sn-2-monoacylglycerols by MGAT may provide a mechanism by which essential fatty acids are retained within specific tissues.

Serum growth hormone and somatomedin-C in patients with bilharzial hepatic fibrosis and post hepatitic cirrhosis

Twenty patients with bilharzial periportal fibrosis, 20 patients with post hepatitic cirrhosis and 20 normal controls were chosen for assessment of serum level of human growth hormone (HGH) before and after insulin induced hypoglycemia and Somatomedin-C (Sm-C). In the first group no statistical significant difference was noticed in HGH before and after insulin test but the basal serum level of Sm-C showed a statistically significant decrease after insulin test. In the second group HGH showed statistical significant increase before and after insulin induced hypoglycemia. Also, the mean serum level of Sm-C showed a statistical significant decrease before and after insulin induced hypoglycemia.

Correlation between the level of serum growth hormone; somatomedin-C; anthropometric measurements and the liver functions in chronic liver diseases

Twenty patients with bilharzial periportal fibrosis (group I); 20 patients with post hepatitic cirrhosis (group II) and 20 normal controls were chosen to study the correlation between the serum level of human growth hormone (GH) and Somatomedin-C (Sm-C); and the anthropometric measurements; liver function tests and various haematological parameters. Group I showed no statistically significant difference in the mean values of serum GH before and after insulin induced hypoglycemia. The basal serum level of Sm-C showed a statistically significant decrease and highly significant decrease after insulin test. A statistically significant positive correlation was evident between the individual values of serum level of GH and Sm-C and the anthropometric measurements, haematological values and liver function tests (r = 0.41). The mean serum level of GH in group 2, showed statistically significant increase before and after insulin test. The mean serum level of Sm-C showed a statistically significant decrease before and after insulin test. A statistically significant negative correlation was found between the individual values of the serum level of GH and Sm-C and the anthropometric measurements, haematological values and liver function tests (r = 0.16).

Seasonal changes in critical enzymes of lipogenesis and triacylglycerol synthesis in the marmot (Marmota flaviventris)

Fatty acid metabolism and triacylglycerol synthesis are critical processes for the survival of hibernating mammals that undergo a prolonged fasting period. Fatty acid synthase, fatty-acid-CoA ligase, diacylglycerol acyltransferase, and monoacylglycerol acyltransferase activities were measured in liver and in white and brown adipose tissue, in order to determine whether enzymes of lipogenesis and triacylglycerol synthesis vary seasonally during hibernation in the yellow-bellied marmot (Marmota flaviventris). Compared with mid-winter hibernation, fatty acid synthase activity was higher in all three tissues during early spring when marmots emerged from hibernation and in mid-summer when they were feeding, consistent with the synthesis of fatty acids from the carbohydrate-rich summer diet. Fatty-acid-CoA ligase and diacylglycerol acyltransferase activities were highest in summer in white adipose tissue when triacylglycerol synthesis would be expected to be high; diacylglycerol acyltransferase activity was also high in brown adipose tissue during spring and summer. In liver, however, diacylglycerol acyltransferase specific activity was highest during hibernation, suggesting that triacylglycerol synthesis may be prominent in liver in winter. Monoacylglycerol acyltransferase activity, which may aid in the retention of essential fatty-acids, was 80-fold higher in liver than in white or brown adipose tissue, but did not vary seasonally. Its dependence on palmitoyl-CoA suggests that a divalent cation might play a role in enzyme activation. The high hepatic diacylglycerol acyltransferase activity during hibernation suggests that the metabolism of very low density lipoprotein may be important in the movement of adipose fatty acids to brown adipose tissue and muscle during the rewarming that occurs periodically during hibernation.(ABSTRACT TRUNCATED AT 250 WORDS)