Persistent moderate methylmalonic aciduria in a patient with methylmalonyl CoA epimerase deficiency.

BACKGROUND: Methylmalonyl CoA epimerase (MCE) deficiency was first reported in 2006 and only a few cases have been reported so far. The clinical spectrum of MCE deficiency ranges from asymptomatic to lifethreatening metabolic decompensation attacks. CASE: Herein we report a patient diagnosed with MCE deficiency with recurrent acute metabolic ketoacidosis attacks and moderate MMA-uria that persisted in periods without decompensation. At presentation, organic acid profiles were dominated by increased 3 hydroxybutyrate. CONCLUSIONS: 3-Oxothiolase deficiency as a main ketolysis defects disorder was initially suspected. However, the subsequently repeated organic acid analyses demonstrated mild and persistent elevation of methylmalonic acid. This report provides a new phenotype of the clinical and biochemical characterization of MCE deficiency.

Long-term follow-up of alkaptonuria patients: single center experience.

OBJECTIVES: Alkaptonuria is a rare autosomal recessive genetic disorder resulting from the deficiency of homogentisate 1,2 dioxygenase (HGD), the third enzyme in the tyrosine degradation pathway. Homogentisic acid produced in excess oxidizes into ochronotic pigment polymer. Accumulation of this pigment in various tissues leads to systemic disease. METHODS: Clinical, laboratory, molecular findings and treatment characteristics of 35 patients followed up in Ege University Pediatric Nutrition, and Metabolism Department with the diagnosis of alkaptonuria were evaluated retrospectively. RESULTS: Twenty-four males (68.57%) and 11 females (31.42%) with a confirmed diagnosis of alkaptonuria from 32 different families were included in the study. We identified 11 different genetic variants; six of these were novel. c.1033C>T, c.676G>A, c.664G>A, c.731_734del, c.1009G>T, c.859_862delins ATAC were not previously reported in the literature. 24 (68.57%) patients only adhered to a low-protein diet in our study group. Seven (20%) patients initiated a low protein diet and NTBC therapy. Mean urinary HGA decreased by 88.7% with nitisinone. No statistical changes were detected in urinary HGA excretion with the low protein diet group. CONCLUSIONS: In our study, alkaptonuria patients were diagnosed at different ages, from infancy to adulthood, and progressed with other systemic involvement in the follow-up. Since the initial period is asymptomatic, giving potentially effective treatment from an early age is under discussion. Raising disease awareness is very important in reducing disease mortality and morbidity rates.

Tetrahydrobiopterin deficiencies: Lesson from clinical experience.

OBJECTIVES: The present study describes clinical, biochemical, molecular genetic data, current treatment strategies and follow-up in nine patients with tetrahydrobiopterin (BH4) deficiency due to various inherited genetic defects. METHODS: We analyzed clinical, biochemical, and molecular data of nine patients with suspected BH4 deficiency. All patients were diagnosed at Ege University Faculty of Medicine in Izmir, Turkey and comprised data collected from 2006 to 2019. The diagnostic laboratory examinations included blood phenylalanine and urinary or plasma pterins, dihydropteridine reductase (DHPR) enzyme activity measurement in dried blood spots, folic acid and monoamine neurotransmitter metabolites in cerebrospinal fluid, as well as DNA sequencing. RESULTS: Among the nine patients, we identified one with autosomal recessive GTP cyclohydrolase I (ar GTPCH) deficiency, two with 6-pyruvoyl-tetrahydropterin synthase (PTPS) deficiency, three with sepiapterin reductase (SR) deficiency, and three with DHPR deficiency. Similar to previous observations, the most common clinical symptoms are developmental delay, intellectual disability, and movement disorders. All patients received treatment with l-dopa and 5-hydroxytryptophan, while only the ar GTPCH, the PTPS, and one DHPR deficient patients were supplemented in addition with BH4. The recommended dose range varies among patients and depends on the type of disease. The consequences of BH4 deficiencies are quite variable; however, early diagnosis and treatment will improve outcomes. CONCLUSIONS: As BH4 deficiencies are rare group of treatable neurometabolic disorders, it is essential to diagnose the underlying (genetic) defect in newborns with hyperphenylalaninemia. Irreversible brain damage and progressive neurological deterioration may occur in untreated or late diagnosed patients. Prognosis could be satisfying in the cases with early diagnose and treatment.

Insulin resistance in children with familial hyperlipidemia.

Background The aim of the study was to investigate whether there is insulin resistance in children with familial hyperlipidemia (FHL) and to determine the factors affecting insulin resistance. Methods Hyperlipidemic children aged between 4 and 18 years and followed up with an FHL diagnosis were included in the study. The children of adults followed up with an FHL diagnosis were also recruited after the screening period. The scanned children were divided into two groups as hyperlipidemic and normolipidemic. A total of 77 patients of whom 52 were hyperlipidemic and 25 were normolipidemic were assessed in the study. Insulin resistance was evaluated (homeostatic model assessment of insulin resistance [HOMA-IR]) by performing the oral glucose tolerance test (OGTT). Results Of the patients, 36 were male and 41 were female; the average age was 11.6±3.9 years, and the body mass index (BMI) was established to be 20.3±4.4. In hyperlipidemic and normolipidemic patients, the following were determined: fasting insulin: 10.6 (±0.89) µU/mL, 4.9 (±0.45) µU/mL (p=0.000); 2-h insulin: 28.7 (±12.7) µU/mL, 18.9 (±10.5) µU/mL (p=0.000); and HOMA-IR: 1.9 (±0.17), 0.86 (±0.7) (p=0.000). No relationship was identified between lipid profiles and insulin resistance. Nevertheless, there was a positive correlation between insulin resistance and apolipoprotein B (Apo B) levels (0.52), and a negative correlation was determined in carnitine levels (-0.64). Conclusions Insulin resistance was established to be higher in children with FHL compared to normolipidemic children. Insulin resistance was not related to lipid phenotypes, but to Apo B levels and carnitine levels. Insulin resistance should be a routine method of evaluation in the follow-up of children with FHL.

Single center experience of biotinidase deficiency: 259 patients and six novel mutations.

Background Biotinidase deficiency (BD) is an autosomal recessively inherited disorder of biotin recycling. It is classified into two levels based on the biotinidase enzyme activity: partial deficiency (10%-30% enzyme activity) and profound deficiency (0%-10% enzyme activity). The aims of this study were to evaluate our patients with BD, identify the spectrum of biotinidase (BTD) gene mutations in Turkish patients and to determine the clinical and laboratory findings of our patients and their follow-up period. Methods A total of 259 patients who were diagnosed with BD were enrolled in the study. One hundred and forty-eight patients were male (57.1%), and 111 patients were female (42.9%). Results The number of patients detected by newborn screening was 221 (85.3%). By family screening, 31 (12%) patients were diagnosed with BD. Seven patients (2.7%) had different initial complaints and were diagnosed with BD. Partial BD was detected in 186 (71.8%) patients, and the profound deficiency was detected in 73 (28.2%) patients. Most of our patients were asymptomatic. The most commonly found variants were p.D444H, p.R157H, c.98_104delinsTCC. The novel mutations which were detected in this study are p.D401N(c.1201G>A), p.A82G (c.245C>G), p.F128S(c.383T>C), c617_619del/TTG (p.Val207del), p.A287T(c.859G>A), p.S491H(c.1471A>G). The most common mutation was p.R157H in profound BD and p.D444H in partial BD. All diagnosed patients were treated with biotin. Conclusions The diagnosis of BD should be based on plasma biotinidase activity and molecular analysis. We determined the clinical and genetic spectra of a large group of patients with BD from Western Turkey. The frequent mutations in our study were similar to the literature. In this study, six novel mutations were described.

The first use of N-carbamylglutamate in a patient with decompensated maple syrup urine disease.

Maple syrup urine disease (MSUD) is a defect in the catabolism of the branched-chain amino acids; leucine, isoleucine, and valine. Affected patients may also develop hyperammonaemia of unknown etiology. This report describes a four-year-old girl with MSUD, who presented with decompensated hyperleucinaemia with hyperammonaemia. The oral administration of the N-acetylglutamate analogue, N-carbamylglutamate (NCG), 200 mg/kg/day as a loading dose, and 100 mg/kg/day as a maintenance dose, in combination with standard therapy resulted in a significant decrease of plasma ammonia levels. This observation suggests that NCG may be an important adjunct to standard therapy in the management of decompensated MSUD patients with high leucine and ammonia levels. Supportive evidence from either randomized controlled trials or a large prospective cohort study is needed to confirm this interesting finding.

Pleural fluid neopterin levels in tuberculous pleurisy.

OBJECTIVES: Neopterin is produced by stimulated macrophages under the influence of gamma interferon of lymphocyte origin. It is regarded as a biochemical marker of cell-mediated immune response. This study was designed to assess the diagnostic value of pleural fluid neopterin levels in tuberculous pleurisy in comparison with adenosine deaminase activity. DESIGN AND METHODS: Pleural fluid adenosine deaminase (ADA) activity and neopterin levels were measured in 16 patients with tuberculous pleurisy (TP) and 19 patients with malignant pleurisy (MP). ADA activity was determined by a colorimetric method, whereas neopterin levels were determined by a reversed-phase liquid chromatography technique. All values were given as median (min-max). RESULTS: The mean age was 45.43+/-20.39 years in the TP group and 60.42+/-11.02 years in the MP group (p=0.026). The median pleural fluid ADA activity was 51.75 U/L (3.50-62.40 U/L) in the TP group and was 2.30 U/L (1-8.20 U/L) in the MP group. The difference was statistically significant (p<0.001). The median pleural fluid neopterin levels were 13.15 nmol/L (1.86-59.50 nmol/L) and 2.44 nmol/L (0.92-27.60 nmol/L) in the TP group and the MP group, respectively (p=0.021). In order to evaluate the diagnostic value of pleural fluid neopterin concentrations, receiver-operating-characteristic curve analysis was performed. CONCLUSION: Pleural fluid neopterin concentration is significantly higher in TP when compared to MP, however when compared, its clinical use as a diagnostic marker is not valuable as ADA.

C-reactive protein and neopterin levels in healthy non-obese adults.

BACKGROUND: Obesity and increased waist-to-hip ratio, emphasizing the importance of truncal obesity, have been found to correlate positively with increased cardiovascular disease risk and mortality. Owing to the inflammatory nature of atherosclerosis, the aim of our study was to find possible correlations between body mass index and waist-to-hip ratio, and the inflammatory markers C-reactive protein (CRP) and neopterin in healthy lean and overweight adults. METHODS: A total of 49 healthy adults (mean age 42.4 +/- 1.8 years, 32 females and 17 males) were classified according to their body mass index (BMI) and waist-to-hip ratio values. CRP and neopterin levels were measured. RESULTS: CRP levels were found to be significantly higher in the group with BMI > or = 25 kg/m2 compared to the group with BMI < 25 kg/m2 (p = 0.014). Subjects with increased waist-to-hip ratio displayed significantly higher serum CRP and neopterin levels (p = 0.014 and p = 0.033, respectively) compared with the group in which the waist-to-hip ratio was < 0.9. A strong positive correlation was found between CRP and BMI in the whole group (r = 0.658, p = 0.0001). CONCLUSIONS: Grouping overweight subjects according to their waist-to-hip ratio, which is an indicator of truncal obesity, seems to be convenient in studying the inflammatory process in relation to the elevation of adipose tissue. Elevated CRP and neopterin levels may be useful in the assessment of cardiovascular risk in overweight as well as obese subjects.

Treatment and prophylaxis with sucralfate ameliorates hypoxia/reoxygenation-induced intestinal injury in pup rats.

BACKGROUND: Sucralfate is widely used as a cytoprotective agent in patients with peptic ulcer and other intestinal mucosal injury. The aim of this study is to investigate whether sucralfate has any effect on the prevention and treatment of hypoxia/reoxygenation-induced intestinal injury. MATERIAL/METHODS: Four groups of 10 1-day-old rat pups were studied. Hypoxia/reoxygenation (H/O)-induced intestinal injury was created. Group 1 was subjected to H/O just after birth and sacrificed at the end of the third day (Treatment Control). Group 2 was subjected to H/O just after birth and treated with sucralfate for 3 days. They were sacrificed at the end of the third day (Treatment). Group 3 was subjected to H/O on the third day after birth and then sacrificed (Prophylaxis Control). Group 4 was treated with sucralfate for the first 3 days, then H/O was created. Just after H/O, the pups were sacrificed (Prophylaxis). The intestinal tissues were harvested for histopathological investigation. Malondialdehyde (MDA) levels in the intestinal tissues were determined. RESULTS: The mucosal injury grades of the treatment and prophylaxis groups were significantly lower than those of control groups (p<0.05). The mean MDA level in the treatment and prophylaxis groups were 0.42+/-0.17 and 0.21+/-0.23 nmol/mg respectively. The MDA levels of both groups were significantly lower than in the control groups (p<0.05). CONCLUSIONS: The present study shows that sucralfate has beneficial effects in an experimental model of hypoxia/reoxygenation-induced intestinal injury.

Effects of L-arginine and L-carnitine in hypoxia/reoxygenation-induced intestinal injury.

BACKGROUND: This study was designed to show the role of oxidative stress, nitric oxide and glutathione-related antioxidant enzymes in hypoxia/reoxygenation (H/R)-induced intestinal injury model in mice and to evaluate the potential benefits of arginine and carnitine supplementation. METHODS: A total of 28 young Balb/c mice were divided into four groups: Group 1 (untreated) was given physiological saline before the experiment; group 2 H/R mice were supplemented with L-arginine; group 3 H/R mice were given L-carnitine for 7 days; and group 4 mice served as controls. At the end of day 7, H/R injury was induced and intestinal tissue malondialdehyde (MDA), nitrate levels and glutathione peroxidase (GSH-Px), glutathione reductase (GR) and glutathione-S-transferase (GST) activities were measured. RESULTS: MDA levels were higher in the untreated animals than in the other three groups. MDA levels were higher in the L-arginine-treated animals than in the L-carnitine-treated animals. Nitrate levels were found to be increased in the L-arginine-treated group when compared to the controls. GSH-Px and GR activities were increased in the untreated, the L-arginine and the L-carnitine-treated H/R groups when compared to the control group. GST activities were indifferent between the groups. CONCLUSIONS: Oxidative stress contributes to the pathogenesis of H/R-induced intestinal injury. The glutathione redox cycle may have a crucial role in the H/R-induced intestinal injury. L-arginine and L-carnitine supplementations ameliorate the histological evidence of H/R-induced intestinal injury and decrease lipid peroxidation but do not alter the glutathione-related antioxidant enzyme activities.

Amlodipine and glutathione cycle in hypercholesterolaemia.

OBJECTIVE: Effects of amlodipine on lipid peroxidation and alterations in glutathione and related enzymes in blood and aortic tissue were investigated in a cholesterol-induced atherosclerotic rabbit model. METHODS AND RESULTS: New Zealand white male rabbits were fed with regular chow (group I), chow supplemented with I% cholesterol (group II), regular chow plus amlodipine 5 mg/kg/day p.o. (group III) and I% cholesterol diet supplemented with amlodipine (group IV) for 8 weeks. Cholesterol, malondialdehyde (MDA), reduced glutathione (GSH), oxidized glutathione (GSSG), glutathione peroxidase (GSH-PX) and glutathione reductase (GSH-Rd) were determined in blood samples drawn before and after the experimental period. Aortic tissue was examined morphologically for atherosclerotic changes and tissue cholesterol, MDA, GSSG, GSH-PX, GSH-Rd and glutathione-S-transferase (GST) were measured. After 8 weeks, blood cholesterol, MDA, GSSG and GSH-PX were elevated in groups II and IV; GSH was reduced in group IV; MDA levels were higher in group II than in group IV. Aortic tissue investigations revealed higher cholesterol and MDA concentrations in group II than in group IV. Morphological examination of aortic tissues exhibited endothelial disarrangement and lipid deposition in group II. Histopathological alterations related to atherogenesis were less in group IV than in group II. CONCLUSIONS: Amlodipine reduced the increase in oxidative stress by inhibiting excessive MDA production. Accelerated glutathione redox cycle activity of erythrocytes from animals supplemented with amlodipine suggests that this drug may reduce oxidative stress by enhancing the glutathione system. However, this drug does not seem to affect the glutathione redox cycle in the aortic tissue.

Pentoxifylline does not prevent hypoxia/reoxygenation-induced necrotizing enterocolitis. An experimental study.

Hypoxia/reoxygenation (H/R)-induced intestinal injury plays a significant role in the development of necrotizing enterocolitis (NEC). We experimentally explored the effect of pentoxifylline (PTX) on an NEC model. Twenty-one newborn rabbits were divided into three groups: group 1 (control), group 2 (H/R) and group 3 (H/R + PTX). Five minutes of reoxygenation following 5 min of hypoxia was performed three times a day during 3 days. Before each H/R procedure in the H/R + PTX group, the rabbits were treated with PTX 25 mg/kg intraperitoneally. Animals were sacrificed on the third day and ileum samples were taken for histopathological examination and biochemical enzyme studies [superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR), and glutathione S-transferase (GST)]. There was a significant difference in the grade and number of the intestinal lesions between controls and the H/R and H/R + PTX groups (p < 0.001), but no significant difference was found between the H/R and the H/R + PTX groups (p > 0.05). Intestinal SOD, GR and GST activities in the H/R and H/R + PTX groups were significantly higher than in the control group (p < 0.05); however, there was no significant difference between the H/R and H/R + PTX groups (p > 0.05). Significantly reduced GPx activity was found in the H/R and H/R + PTX groups compared with the controls (p < 0.05). No significant difference in GPx activity existed between the H/R group and the H/R + PTX group (p > 0.05). Ischemia/reperfusion injury was responsible for mediating hypoxia-induced intestinal necrosis in NEC and PTX pretreatment did not have a protective effect on NEC.

Association between serum paraoxonase activity and oxidative stress in acute coronary syndromes.

OBJECTIVE: The oxidation of low-density lipoprotein (LDL) is believed to have a central role in atherogenesis. Under oxidative stress not only LDL, but all other serum lipids are exposed to oxidation. High-density lipoprotein (HDL)-associated paraoxonase (PON1) was shown to inhibit LDL and HDL oxidation. We investigated the relationship between PON1 and oxidative stress in acute myocardial infarction and unstable angina in a comparative fashion. METHODS AND RESULTS: Activities of PON1, concentrations of malondialdehyde (MDA), lipids and lipoproteins were measured in patients (38 subjects with acute myocardial infarction and 33 subjects with unstable angina pectoris) and in age- and sex-matched controls (32 subjects). Serum PONI activity was significantly lower in patients than in controls (p < 0.001). Patients had significantly increased serum MDA concentrations (p < 0.001) and there were strong negative correlations (p < 0.001) between serum PON1 and MDA levels in the acute myocardial infarction group (r = -0.673), in the unstable angina pectoris group (r = -0.868) and in healthy controls (r = -0.778). Serum HDL-cholesterol (HDL-C) concentrations were lower in patients than controls (p < 0.05). No correlation was observed between PON1 and HDL-C levels in patients or controls. Apo A I concentrations were significantly lower in the patient groups (p < 0.01), but were insignificant between patients with AMI and UAP. Apo A-I and PON1 levels did not show any correlation. Apo B concentrations were lowest in the healthy controls, higher in the UAPgroup and highest in the AMI group (p < 0.001). In the acute myocardial infarction group LDL/apo B ratio was lower than in healthy controls and in the UAP group, suggesting smaller LDL particle size. CONCLUSIONS: Results of this study indicate that lower serum PON1 activity is associated with oxidative stress and the activity of PON1 is not related to HDL-cholesterol.

Serum and urinary nitric oxide in Type 2 diabetes with or without microalbuminuria: relation to glomerular hyperfiltration.

BACKGROUND: Glomerular hyperfiltration is considered as one of the pathophysiological mechanisms for the development of diabetic nephropathy. Oxidative stress is enhanced in patients with diabetes mellitus. Reportedly, nitric oxide (NO) might be involved in the pathogenesis of hyperfiltration. We investigated the relationship between hyperfiltration and NO system, and malondialdehyde (MDA) levels in Type 2 diabetics with/without microalbuminuria. METHODS: In 39 microalbuminuric, 29 normoalbuminuric Type 2 diabetic patients and 32 healthy controls, serum creatinine, nitrite, nitrate, urinary microalbumin, nitrite, nitrate, plasma MDA and estimated glomerular filtration rate (EGFR) values, calculated according to the Cockcroft and Gault formula, were recorded. RESULTS: Serum and urine NO levels were higher in both microalbuminurics and normoalbuminurics than controls. There were no significant differences in EGFR between groups. However, hyperfiltration was determined in 31% of normoalbuminurics and 20% of microalbuminurics. Serum and urine NO levels were higher in patients with hyperfiltration. Plasma MDA levels were significantly elevated in both microalbuminurics and normoalbuminurics when compared with controls. Serum glucose and microalbuminuria were positively correlated in microalbuminuric diabetics. Serum NO levels were also positively correlated with EGFR in both normoalbuminurics and microalbuminurics. HbA1c levels were positively correlated with both urinary albumin excretion and plasma MDA levels in normoalbuminuric diabetics. CONCLUSIONS: Hyperglycemia is associated with an increased NO biosynthesis and lipid peroxidation. Increased oxidative stress may contribute to the high NO levels in Type 2 diabetes. Furthermore, the high NO levels may lead to hyperfiltration and hyperperfusion, which in turn leads to an increase in urinary albumin excretion and thus causes progression of nephropathy in early Type 2 diabetes.

Effects of the calcium channel blocker amlodipine on serum and aortic cholesterol, lipid peroxidation, antioxidant status and aortic histology in cholesterol-fed rabbits.

Reactive oxygen metabolites and oxidized fatty acids are proinflammatory and are involved in the pathophysiology of atherosclerosis. Amlodipine, a unique third-generation dihydropyridine-type calcium channel blocker, seems to exert atheroprotective effects through its antioxidant properties related to its chemical structure and independent of its calcium channel-blocking effect. In this study, the interactions of amlodipine with major cellular antioxidants were investigated in order to elucidate the mechanisms underlying its atheroprotective effects. New Zealand white male rabbits were fed regular chow (group 1), chow with 1% cholesterol (group 2), regular chow plus 5 mg/kg/day amlodipine per os (group 3) and 1% cholesterol plus amlodipine (group 4) for 8 weeks. Total cholesterol, malondialdehyde (MDA) and vitamin E concentrations and catalase and superoxide dismutase (SOD) activities were determined in blood drawn before and after the experimental period. Aortic tissue was examined for atherosclerotic changes and aortic total cholesterol, MDA, catalase and SOD were determined. At the end of the 8-week treatment period, serum total cholesterol and plasma MDA were elevated in groups 2 and 4. In group 2, serum vitamin E and plasma SOD diminished (p < 0.05) and catalase increased (p < 0.05). In group 4, SOD activity increased at the end of treatment. MDA levels were lower and plasma SOD activities were higher in group 4 than in group 2. Aortic tissue investigations revealed higher total cholesterol and MDA concentrations and catalase activities in group 2 than in group 4, and the highest tissue SOD activity was recorded in group 4 (p < 0.05 for all comparisons). Morphological examination of aortic tissues exhibited endothelial disarrangement and lipid deposition in group 2. Histopathological alterations related to atherogenesis were less in group 4 than in group 2. Amlodipine seems to exert atheroprotective effects by reducing aortic cholesterol accumulation and blood and aortic lipid peroxidation, enhancing SOD activity both in blood and aortic tissue and suppressing the consumption of vitamin E. On the other hand, the suppression of catalase activity in blood and the aorta interferes with the drug's well-known antioxidant effects.

Comparison of the effects of dietary saturated, mono-, and n-6 polyunsaturated fatty acids on blood lipid profile, oxidant stress, prostanoid synthesis and aortic histology in rabbits.

BACKGROUND/AIMS: To compare the effects of saturated, monounsaturated and polyunsaturated n-6 fatty acid-enriched diets on the development of atherosclerosis and thrombosis in New Zealand white male rabbits, 3- to 6-month-old animals were supplemented daily (10 g/100 g diet) with butter (n = 8), olive oil (n = 8) or corn oil (n = 8) by oral administration for 7 weeks. METHODS: Total cholesterol (TC), HDL- (HDL-C) and LDL-cholesterol (LDL-C), triglycerides (TG), apolipoprotein A-1 (ApoA-1), apolipoprotein B (ApoB), lipid peroxides as thiobarbituric acid-reactive substances (TBARS), thromboxane B2 (TXB2) and 6-ketoprostaglandin F(1alpha) (6-ketoPGF(1alpha)) concentrations were determined in blood samples drawn before and after each group was fed the different dietary regimens. Histological examination was performed on the aortic tissues. RESULTS: After 7 weeks, TC, ApoB and TXB2 increased significantly (p < 0.05) in the butter-fed animals compared to pre-experimental concentrations. Olive oil administration lead to a significant (p < 0.05) decrease in TC and ApoB levels. The corn oil-enriched diet decreased TC, LDL-C concentrations, TC/HDL-C ratios and 6-ketoPGF(1alpha) (stable metabolite of prostacyclin-PGI2; p < 0.05 for all) but increased TBARS levels and TXB2/6-ketoPGF(1alpha) ratios. Light microscopic findings were in accordance with these biochemical alterations. CONCLUSION: Although effective in lipid lowering, corn oil increased oxidant stress as evidenced by increased TBARS and induced endothelial damage which lead to a reduction in PGI2 synthesis and consequently to an increase in the TXB2/6-ketoPGF(1alpha) ratio. Olive oil administration did not induce oxidant stress and it had no affect on PGI2 and TXB2 levels which are implicated in platelet aggregation. These findings suggest that oleic acid is more effective than linoleic acid in the protection of endothelial integrity.

Association between homocysteinemia and renal function in patients with type 2 diabetes mellitus.

Homocysteinemia is an independent risk factor for cardiovascular disease, but information on its association with type 2 diabetes and mild renal dysfunction is limited. Plasma total homocysteine (tHcy) concentration is partly determined by renal plasma clearance. Serum cystatin C (Cys C) concentration has been introduced as a marker of renal function, specifically as an indicator of glomerular filtration rate (GFR). The aim of this study was to explore the relationships among tHcy, creatinine clearance (Ccr), serum Cys C, and microalbuminuria in a population with type 2 diabetes. Fasting plasma tHcy, serum homocysteine-related vitamins (folate and vitamin B12), serum Cys C, serum creatinine, urine microalbumin, and creatinine clearance were determined in 75 type 2 diabetic patients and 40 healthy control subjects. The patients were assigned to two groups based on urinary albumin excretion (UAE): normoalbuminuric (NAU, UAE < 30 mg/24 hr, n = 35) and microalbuminuric (MAU, UAE 30-300 mg/24 hr, n = 40). Ccr was calculated using the Cockroft-Gault formula. Plasma Hcy levels were determined by HPLC with fluorescence detection and serum Cys C by automated particle enhanced immunoturbidimetry. Plasma tHcy levels were significantly higher in normoalbuminuric and microalbuminuric patients than in controls (10.64 +/- 0.53, 13.29 +/- 0.78, 6.91 +/- 0.37 mmol/L, respectively). Serum Cys C levels in microalbuminuric diabetics were higher than in normoalbuminurics and controls (1.36 +/- 0.06, 1.12 +/- 0.04, 1.10 +/- 0.06 mg/ L, respectively). Positive correlations were noted between tHcy and Cys C levels in normoalbuminuric and microalbuminuric diabetics (r = 0.72, r = 0.64, respectively). Homocysteine and creatinine concentrations were correlated in both diabetic groups (r = 0.89, r = 0.93, NAU and MAU, respectively). Elevated plasma total homocysteine concentrations in type 2 diabetics suggest an association between homocysteinemia and deterioration of renal function, evidenced by increased serum creatinine and Cys C, Ccr, and microalbuminuria. These findings implicate homocysteinemia in the relationship between diabetic nephropathy and cardiovascular complications of diabetes.

Protective effect of dietary supplementation with L-arginine and L-carnitine on hypoxia/reoxygenation-induced necrotizing enterocolitis in young mice.

Oxygen-derived free radicals are important components of gastrointestinal injury in necrotizing enterocolitis (NEC). In the present investigation, we examined the protective actions of L-arginine, a nitric oxide synthase substrate, and L-carnitine against hypoxia-reoxygenation (H/R) induced NEC in young mice. Young mice were divided into four groups: group 1 mice were subjected to H/R only; group 2 H/R mice were supplemented with L-arginine in the drinking water (2 g/l) for 7 days; group 3 H/R mice were given L-carnitine solution in water (50 mg/kg p.o.) for 7 days, and group 4 mice served as controls. Hypoxia was induced by placing the mice in a 100% CO(2) chamber for 5 min. After hypoxia, the mice were reoxygenated for 10 min with 100% oxygen. We examined the intestinal lesions by light microscopy and measured the intestinal generation of thiobarbituric acid reactive substances (TBARS) and the activities of superoxide dismutase and catalase in the H/R-induced model of NEC. In both L-arginine and L-carnitine groups, the NEC-induced intestinal tissue damage was greatly attenuated, with necrosis limited partially to the mucosa. The tissue TBARS level was significantly higher in group 1 than in any of the other groups (p < 0.001). However, those treated with L-arginine and L-carnitine had TBARS levels similar to those in the control animals. An increased tissue concentration of nitrate, a stable metabolite of nitric oxide, was found in the L-arginine-supplemented group as compared with the control group (p < 0.05). Both superoxide dismutase and catalase activities in the intestine were similar in H/R groups when compared with the intestine of control animals. The present study suggests that oxygen-derived free radicals are involved in the pathogenesis of H/R-induced NEC. This study also shows that dietary supplementation with L-arginine and L-carnitine ameliorates the histological evidence of H/R-induced intestinal injury and significantly decreases lipid peroxidation in H/R-induced bowel injury. Based on these findings, the beneficial effects of L-arginine and L-carnitine in this model may be mediated via mechanisms preventing free radical damage.