MTHFR, TS and XRCC1 genetic variants may affect survival in patients with myelodysplastic syndromes treated with supportive care or azacitidine.

We evaluated the impact of genomic polymorphisms in folate-metabolizing, DNA synthesis and DNA repair enzymes on the clinical outcome of 108 patients with myelodysplastic syndromes (MDS) receiving best supportive care (BSC) or azacitidine. A statistically significant association between methylenetetrahydrofolate reductase (MTHFR) 677T/T, thymidylate synthase (TS) 5'-untranslated region (UTR) 3RG, TS 3'-UTR -6 bp/-6 bp, XRCC1 399G/G genotypes and short survival was found in patients receiving BSC by multivariate analysis (P<0.001; P=0.026; P=0.058; P=0.024). MTHFR 677T/T, TS 3'-UTR -6 bp/-6 bp and XRCC1 399G/G genotypes were associated with short survival in patients receiving azacitidine by multivariate analysis (P<0.001; P=0.004; P=0.002). We then performed an exploratory analysis to evaluate the effect of the simultaneous presence of multiple adverse variant genotypes. Interestingly, patients with ⩾1 adverse genetic variants had a short survival, independently from their International Prognostic Scoring System (IPSS) and therapy received. To our knowledge, this is the first study showing that polymorphisms in folate-metabolizing pathway, DNA synthesis and DNA repair genes could influence survival of MDS patients.

Feasibility of allogeneic stem-cell transplantation after azacitidine bridge in higher-risk myelodysplastic syndromes and low blast count acute myeloid leukemia: results of the BMT-AZA prospective study.

BACKGROUND: Allogeneic stem-cell transplantation (HSCT) is the only curative treatment in myelodysplastic syndromes (MDS). Azacitidine (AZA) is increasingly used prior to HSCT, however in Europe it is only approved for patients who are not eligible for HSCT. PATIENTS AND METHODS: We conducted a phase II multicenter study to prospectively evaluate the feasibility of HSCT after treatment with AZA in 70 patients with a myelodysplastic syndrome (MDS), 19 with acute myeloid leukemia (AML), and 8 with chronic myelomonocytic leukemia (CMML). After a median of four cycles (range 1-11): 24% of patients achieved complete remission, 14% partial remission, 8% hematologic improvement, 32% had stable and 22% progressive disease. Ten patients discontinued treatment before the planned four cycles, due to an adverse event in nine cases. RESULTS: A HSC donor was identified in 73 patients, and HSCT was performed in 54 patients (74% of patients with a donor). Main reasons for turning down HSCT were lack of a donor, an adverse event, or progressive disease (9, 12, and 16 patients, respectively). At a median follow-up of 20.5 months from enrolment, response to AZA was the only independent prognostic factor for survival. Compared to baseline assessment, AZA treatment did not affect patients' comorbidities at HSCT: the HCT-CI remained stable in 62% patients, and worsened or improved in 23% and 15% of patients, respectively. CONCLUSIONS: Our study shows that HSCT is feasible in the majority of patients with HR-MDS/AML/CMML-2 after AZA treatment. As matched unrelated donor was the most frequent source of donor cells, the time between diagnosis and HSCT needed for donor search could be 'bridged' using azacitidine. These data show that AZA prior to HSCT could be a better option than intensive chemotherapy in higher-risk MDS. The trial has been registered with the EudraCT number 2010-019673-1.

The absence of polymorphisms in ADRB3, UCP1, PPARγ, and ADIPOQ genes protects morbid obese patients toward insulin resistance.

BACKGROUND AND AIMS: The insulin resistance (IR) is a major metabolic impairment in severe obesity, a multifactorial disease in which the importance of the effect of single nucleotide polymorphisms (SNP) associations in different rather than individual genes was established. The aim of this study was to test the predictive value of presence/absence of polymorphisms/ variants in ß3-adrenergic receptor (ADRB3), uncoupling protein 1 (UCP1), peroxisome proliferator-activated receptor γ (PPARγ), and adiponectin (ADIPOQ) genes in diagnosing the IR in obesity. SUBJECTS AND METHODS: We studied 112 (40 males, 72 females) severely obese (body mass index: 48.5±7.5 kg/m2) subjects recruited from the outpatient obesity clinic of Federico II University Hospital in Naples. Genomic DNA was extracted from peripheral leukocytes with a commercial kit. The gene polymorphisms Trp64Arg in ADRB3, -3826 A>G in UCP1, Pro12Ala in PPARγ, and c.268G>A, c.331T>C, and c.334C>T in ADIPOQ were characterized by TaqMan assay or by direct sequencing (ADIPOQ). RESULTS AND CONCLUSION: Our results demonstrate that -3826A>G UCP1 polymorphism is associated with IR in morbid obesity. Further, the lack of any polymorphisms, Trp64Arg in ADRB3 and/or -3826 A>G in UCP1 and/or Pro12Ala in PPARγ and/or c.268G>A, c.331T>C and c.334C>T in ADIPOQ, appears a useful prognostic factor (NPV=100%) toward the IR onset in these obese patients representing a further parameter for an earlier and appropriate therapy.

Circulating levels of cytochrome C, gamma-glutamyl transferase, triglycerides and unconjugated bilirubin in overweight/obese patients with non-alcoholic fatty liver disease.

Non-alcoholic fatty liver disease, characterized by hepatocyte apoptosis, is distinct in fatty liver and non-alcoholic steatohepatitis, the more severe form. Apoptotic cell death is caspase-dependent and associated with mitochondrial membrane depolarization and cytochrome c release. Adhering to the hypothesis that the exposure of hepatocytes to free fatty acids, resulting in increased ROS production and mitochondrial damage, is balanced by the presence of antioxidant substances, circulating levels of gamma-glutamyl transferase, cytochrome c, triglycerides and unconjugated bilirubin were explored in patients suffering from non-alcoholic fatty liver disease with different severity. One hundred and eighty-six consecutive patients who presented recent ultrasound feature of bright liver without any liver disease of known origin were enrolled, eighty-nine of whom underwent liver biopsy. Forty-five subjects were allocated on the basis of histology in fatty liver group while 44 patients formed the group with non-alcoholic steatohepatitis. A cohort of 27 young, lean, apparently healthy individuals was selected as control group. The levels of gamma-glutamyl transferase were normal or slightly increased, while unconjugated bilirubin concentrations were elevated in all the spectra of non-alcoholic fatty liver disease. Comparing the present results with relevant findings from other studies dealing with diseases characterized by apoptosis, we did not find high circulating levels of cytochrome c in non-alcoholic fatty liver disease. What is more, our patients, categorized as suffering from simple fatty liver or from the more severe non-alcoholic steatohepatitis, had similar levels of cytochrome c and gamma-glutamyl transferase, p=0.19 and 0.11. Serum triglycerides were higher in patients with non-alcoholic fatty liver disease than in the healthy group, p=0.001. These findings likely reflect a balance between oxidative stress and anti-oxidant response rather than a lack of reliability of cytochrome c as a reliable biomarker of mitochondrial damage.

UCP1 -3826 AG+GG genotypes, adiponectin, and leptin/adiponectin ratio in severe obesity.

BACKGROUND AND AIMS: Non-alcoholic fatty liver disease (NAFLD) and metabolic syndrome (MS) are well-recognized complications of obesity. This study was designed to evaluate the role of the UCP1 -3826 A>G polymorphism, adiponectin levels, leptin/adiponectin ratio (L/A), and main biochemical parameters in 102 unrelated severely obese adults [61 females and 41 males, median body mass index (BMI) = 47.8 kg/m2] with NAFLD, with (MS+) or without MS (MS-) from Southern Italy. SUBJECT AND METHODS: The UCP1 polymorphism was tested by the TaqMan method, main biochemical parameters by routinary methods, adiponectin, and leptin serum levels by enzyme-linked immunosorbent assay. MS was diagnosed according to the American Heart Association criteria, liver steatosis was detected by ultrasound. RESULTS: MS was present in 53% male and 66% female obese patients. Only total cholesterol (p=0.04 males and p=0.002 females) and L/A ratio (p=0.03 males) differed between MS+ and MS- obese patients. At multivariate analysis, severe liver steatosis was significantly associated with: UCP1 (AG+GG) genotypes [odds ratio-confidence interval (OR-CI): 4.25; 1.12-16.13], MS (OR-CI: 8.47; 1.78-40.25), low adiponectin levels (OR-CI: 0.92; 0.87-0.98), high alanine aminotransferase levels (OR-CI: 1.03; 1.00-1.06), age (ORCI: 1.08; 1.00-1.15), and male gender (OR-CI: 10.78; 1.61- 71.96). CONCLUSION: In addition to traditional factors, total cholesterol and L/A ratio appear to contribute to MS characterization in severe obesity. Furthermore, the UCP1 (AG+GG) genotypes and low adiponectin levels could predispose to a more severe liver steatosis independently of MS presence. Based on our data, polymorphic UCP1 (AG+GG) obese patients with low adiponectin levels appear to be high-risk subjects for worsening of liver steatosis, a NAFLD, possibly requiring a second-step evaluation by liver biopsy.

Molecular analysis of the adiponectin gene in severely obese patients from southern Italy.

BACKGROUND: Severe obesity is a major worldwide public health concern affecting 0.5-5% of the adult population. Adiponectin (Acpr30), an adipokine secreted from adipocytes, shows pleiotropic beneficial effects on obesity and related disorders. In this study, sequence analysis of Acpr30 gene (ACDC) was performed in a highly selected population of severely obese young adult patients from Southern Italy to investigate the associations between polymorphisms in the ACDC gene and the development of severe obesity concomitantly with other features of the metabolic syndrome. METHODS: The ACDC gene was analyzed by direct sequencing in the severely obese patients (n=220) and compared to healthy controls (n=116). The associations between the ACDC gene single-nucleotide polymorphisms (SNPs) and the levels of serum Acpr30 as well as the correlation with the presence of severe obesity jointly associated with other features of the metabolic syndrome were also investigated. Total serum Acpr30 concentrations were measured by the ELISA method. RESULTS: ACDC gene molecular screening revealed the presence of previously described SNPs and a new nucleotide alteration, c.355T>G, leading to a protein variant, p.L119V. Measurement of serum concentration of Acpr30 demonstrated lower levels of Acpr30 in the obese population compared to controls (30.5+/-28.3 vs. 43.9+/-35.7 microg/ml, p<0.01); in particular, significantly lower Acpr30 concentrations were observed in obese patients bearing c.-11377C>G SNP CG+GG genotypes than in those with CC genotype (22.9+/-20.5 vs. 33.1+/-29.4 microg/ml, p<0.05). CONCLUSIONS: Our results confirmed that low serum levels of Acpr30 are related to severe obesity and a difference in protein expression is associated with variants in ACDC gene promoter region.

Alcohol use and abuse: a cross-sectional study among Italian adolescents.

INTRODUCTION: Alcohol is recognized as one of four major risk factors for non-communicable diseases. Exposure to alcoholic beverages during the adolescence has been linked to increased heavier drinking habits: obviously, the age of alcohol initiation resulted an important determinant of alcohol dependence. The aim of this study is to analyze knowledge, attitudes and practices in alcohol habit of adolescent population. METHODS: 943 students from 13 schools (middle and upper secondary schools) of the Bari district were enrolled in the study: in each school one class for each age was randomly selected. The research was carried out by an anonymous, self-administered questionnaire which investigated alcohol consumption, knowledge of alcohol consumption of parents and knowledge of the law regulating alcohol consumption. RESULTS: 34.8% (328) have never consumed alcoholic drinks while 65.2% (615) declare the use of alcohol; the average age of alcohol initiation was 12.2 years. 35.7% (329/921) of mothers and 36.6% (335/915) of fathers drink alcohol only on special occasions. 17.9% (168/939) considered that alcohol could be free sale at all while 16.4% (154/939) reported that sale is forbidden for children under 14. CONCLUSIONS: The higher prevalence of alcohol habits and the poor knowledge on alcohol law seemed to indicated the need of improving public health efforts in the prevention of alcohol consumption among Italian adolescents.

A phase II, multicentre trial of decitabine in higher-risk chronic myelomonocytic leukemia.

Chronic myelomonocytic leukemia (CMML) is a complex clonal hematological disorder classified among myelodysplastic (MDS)/myeloproliferative neoplasms. Prognosis is poor and there is a lack of effective treatments. The hypomethylating agent decitabine has shown activity against MDS and elderly acute myeloid leukemia, but there is little data focusing specifically on its efficacy in CMML. In this prospective, phase 2 Italian study, CMML patients received intravenous decitabine 20 mg/m2 per day on Days 1-5 of a 28-day treatment cycle. Response was evaluated after four and six cycles; patients responding at the end of six cycles could continue treatment with decitabine. Forty-three patients were enrolled; >50% were high-risk according to four CMML-specific scoring systems. In the intent-to-treat population (n=42), the overall response rate after six cycles was 47.6%, with seven complete responses (16.6%), eight marrow responses (19%), one partial response (2.4%) and four hematological improvements (9.5%). After a median follow-up of 51.5 months (range: 44.4-57.2), median overall survival was 17 months, with responders having a significantly longer survival than non-responders (P=0.02). Grade 3/4 anemia, neutropenia and thrombocytopenia occurred in 28.6%, 50% and 38% of patients, respectively. Decitabine appears to be an effective and well-tolerated treatment for patients with high-risk CMML.

Metabolic syndrome and ADRB3 gene polymorphism in severely obese patients from South Italy.

OBJECTIVE: To evaluate the prevalence of beta(3)-adrenergic receptor (ADRB3) Trp64Arg polymorphism and its relationship with the metabolic syndrome in severe obesity. DESIGN: Cross-sectional outpatients study. PATIENTS AND METHODS: In 265 (100 men) severely obese non-diabetic subjects and 78 (25 men) healthy volunteers, genomic DNA was isolated from peripheral leukocytes. In obese patients, plasma concentrations of leptin, lipids, glucose and insulin, the homeostasis model assessment index and blood pressure have been measured. The Trp64Arg mutation was identified with the real-time TaqMan method. RESULTS: Neither genotype distribution nor allele frequency differed between the two groups. The metabolic syndrome prevalence was 59% in obese subjects, and was higher in men than in women (65 vs 55%: P=0.03). The body mass index (BMI) was related to age tertiles (beta=0.08; P<0.001; multiple linear regression) in Trp64Arg-positive obese subjects. CONCLUSION: We confirm the high prevalence of the metabolic syndrome among severely obese subjects. ADRB3 polymorphism was significantly related to insulin resistance only in obese male subjects. Moreover, increased BMI was related to age in obese subjects with the ADRB3 polymorphism.

Frequent elevation of Akt kinase phosphorylation in blood marrow and peripheral blood mononuclear cells from high-risk myelodysplastic syndrome patients.

The serine/threonine kinase Akt, a downstream effector of phosphatidylinositol 3-kinase (PI3K), is known to play an important role in antiapoptotic signaling and has been implicated in the aggressiveness of a number of different human cancers including acute myeloid leukemia (AML). The progression of myelodysplastic syndromes (MDSs) to AML is thought to be associated with abrogation of apoptotic control mechanisms. However, little is known about signal transduction pathways which may be involved in enhanced survival of MDS cells. In this report, we have performed immunocytochemical and flow cytometric analysis to evaluate the levels of activated Akt in bone marrow or peripheral blood mononuclear cells from patients diagnosed with MDS. We observed high levels of Ser473 phosphorylated Akt (p-Akt) staining in 90% of the cases (n=22) diagnosed as high-risk MDS, whereas mononuclear cells from normal bone marrow or low-risk MDS patients showed low or absent Ser473 p-Akt staining. Furthermore, all high-risk MDS patients also demonstrated high expression of the Class I PI3K p110delta catalytic subunit and a decreased expression of PTEN. Taken together, our results suggest that Akt activation might be one of the factors contributing to the decreased apoptosis rate observed in patients with high-risk MDS.

The improvement of large High-Density Lipoprotein (HDL) particle levels, and presumably HDL metabolism, depend on effects of low-carbohydrate diet and weight loss.

Depressed levels of atheroprotective large HDL particles are common in obesity and cardiovascular disease (CVD). Increases in large HDL particles are favourably associated with reduced CVD event risk and coronary plaque burden. The objective of the study is to compare the effectiveness of low-carbohydrate diets and weight loss for increasing blood levels of large HDL particles at 1 year. This study was performed by screening for body mass index (BMI) and metabolic syndrome in 160 consecutive subjects referred to our out-patient Metabolic Unit in South Italy. We administered dietary advice to four small groups rather than individually. A single team comprised of a dietitian and physician administered diet-specific advice to each group. Large HDL particles at baseline and 1 year were measured using two-dimensional gel electrophoresis. Dietary intake was assessed via 3-day diet records. Although 1-year weight loss did not differ between diet groups (mean 4.4 %), increases in large HDL particles paralleled the degree of carbohydrate restriction across the four diets (p<0.001 for trend). Regression analysis indicated that magnitude of carbohydrate restriction (percentage of calories as carbohydrate at 1 year) and weight loss were each independent predictors of 1-year increases in large HDL concentration. Changes in HDL cholesterol concentration were modestly correlated with changes in large HDL particle concentration (r=0.47, p=.001). In conclusion, reduction of excess dietary carbohydrate and body weight improved large HDL levels. Comparison trials with cardiovascular outcomes are needed to more fully evaluate these findings.

Retraction: The improvement of large High-Density Lipoprotein (HDL) particle levels, and presumably HDL metabolism, depend on effects of low-carbohydrate diet and weight loss.

[This retracts the article DOI: 10.17179/excli2015-642.].

Incorporation of [14C]hypoxanthine into cardiac adenine nucleotides: effect of aging and post-ischemic reperfusion.

In order to investigate whether the 'hypoxanthine salvage' pathway of the cardiac muscle is modified with age, we aerobically perfused isolated hearts of 4-month- and 22-month-old male Wistar rats for 20 min with 0.18 microM [14C]hypoxanthine. A second group of hearts was subjected to a 30-min ischemic perfusion (95% reduction of the coronary flow), followed by 20 min of reperfusion. In this last 20 min, the perfusate contained the same concentration of [14C]hypoxanthine used under the aerobic condition. After 20 min of aerobic perfusion the myocardial levels of ATP were significantly lower (15%) in aged than young rat hearts, whilst no age-related differences were observed at the end of the reperfusion. In the young rats the incorporation of the isotope into ATP, ADP, and AMP was significantly higher (192%, 226%, and 300%, respectively), after 20 min of reperfusion with respect to the aerobic values. On the contrary, in the aged hearts, no significant change in the rate of [14C]-incorporation into ATP was observed during reperfusion, despite an increase of the [14C]-incorporation into ADP and AMP. Moreover, the content of each labeled adenine nucleotide was significantly higher in aged than young hearts at the end of the aerobic period, whereas the incorporation of the labeled hypoxanthine was not affected by age after 20 min of reperfusion. The release of uric acid into coronary effluents was greater (50%) in aged than young rats during the reperfusion period, but no age-dependent differences in the isotope incorporation into uric acid were observed. These data indicate that in the aged rat heart, perfused under aerobic conditions, there is an increased incorporation of hypoxanthine into ATP, although it does not further increase during postischemic reperfusion.

Splenectomy for patients with myelofibrosis with myeloid metaplasia: pretreatment variables and outcome prediction.

Since according to the early studies, the outcome after splenectomy in the individual patient with myelofibrosis with myeloid metaplasia (MMM) is unpredictable, we assessed retrospectively the pre-intervention characteristics that best predicted adverse events, hematological consequences, and survival in 71 splenectomized MMM patients. The findings indicate that the operative risk of splenectomy for both mortality (8.4%) and morbidity (39.3%) was unpredictable. New hemorrhagic or thrombotic complications occurred in 16.9% of surviving patients and were predicted by age < 50 years, a normal to high platelet count (> 200 x 10(9)/l) and huge splenomegaly (> 16 cm from the costal margin). Massive liver enlargement occurred in 24% of patients and has to be expected in patients splenectomized for transfusion-dependent anemia. Anemia improved substantially in 45% and 52% of patients at 3 months and at 1 year, respectively, and was predicted by severe anemia, low platelet count (< 100 x 10(9)/l) or normal to high white blood cell (WBC) count (> 4 x 10(9)/l). Survival from splenectomy was superior in patients < 45 years with WBC < 10 x 10(9)/l count. An unexpectedly high rate of blastic transformation was observed. It accounted for 42.8% of the deaths. The results suggest trials for prophylactic cytoreductive treatment in young patients and when platelet count is normal to increased. Further study is needed for elucidating the possible role played by splenectomy in inducing blastic transformation.

Clinical efficacy and antiangiogenic activity of thalidomide in myelofibrosis with myeloid metaplasia. A pilot study.

Increased neoangiogenesis has been reported in myelofibrosis with myeloid metaplasia (MMM). Thus we studied the effects of thalidomide, an antiangiogenic drug, in 12 MMM patients. Before treatment, all the cases showed a significantly increased micro-vessel density (MVD); in all eight tested cases bFGF and VEGF plasma levels were higher than controls. All patients presented disease progression in the last 3 months with standard therapy, regarding splenomegaly, anemia and/or thrombocytopenia and/or hyperleukocytosis. Thalidomide was administered at daily doses increasing from 100 to 600 mg. Eleven out of 12 patients were evaluable. No progression of disease was seen during the treatment in any case. In particular, spleen size decreased in 7/11 patients, anemia improved in 3/4 (two are now transfusion independent), thrombocytopenia in 2/2 and hyperleukocytosis in 2/5 patients. Side-effects were frequent, although not severe. After treatment, VEGF and bFGF plasma levels varied widely and in selected cases decreased. In particular, VEGF and/or bFGF decreased in 4/5 responders and in 1/3 non-responders. Moreover, MVD significantly decreased in all the responders evaluated after treatment. We conclude that thalidomide is a feasible therapy in MMM patients and looks promising at least to control the growth progression of disease.

Effect of age on phosphorylated compounds and mechanical activity of isolated rat heart: a 31P-NMR study.

OBJECTIVE: The aim was to test the hypothesis that aging may change the function and energetics of isolated hearts subjected to an increased work load induced by varying the calcium concentration ([Ca2+]) in the perfusion fluid from 0.5 to 1.0, 1.5, or 2.0 mM. METHODS: Female Wistar rats aged 4, 12-14, and 22-24 months were used. Their hearts were perfused through the aorta and changes in myocardial phosphorylated compound concentration were measured by means of 31P-nuclear magnetic resonance spectroscopy and biochemical analysis. Myocardial contractility was measured in situ in closed heart anaesthetised animals and was followed in vitro during perfusion. RESULTS: The contractile indices measured in situ revealed a decrease with aging of the left ventricular developed pressure and dP/dtmax, while heart rate did not show any significant difference. In all age groups the stepwise increase in [Ca2+] caused a graded increase in left ventricular pressure in the perfused hearts. In aged rats, the left ventricular pressure associated with the different concentrations of Ca2+ was significantly lower than in young rats. In all three groups the myocardial content of inorganic phosphorus (Pi) increased in response to a rise in [Ca2+] and left ventricular pressure. The ATP content of the hearts remained constant in all three groups at each value of [Ca2+] induced left ventricular pressure. However, both ATP and total adenine nucleotide contents of the hearts were lower in aged rats. When the alteration in Pi due to each increase in [Ca2+] was expressed in relation to the rise in left ventricular developed pressure, this relationship was not significantly different in the three groups of hearts. CONCLUSIONS: The reduced mechanical activity of aged rat hearts is not due to a diminished efficiency of the mechanisms transferring high energy phosphates.

Age-dependent differences of ATP breakdown and ATP-catabolite release in ischemic and reperfused hearts.

The hearts of young (6 months) and aged (24 months) rats, paced at a frequency of 300 bpm, were perfused by the Langendorff technique and subjected to: 20 min of equilibration perfusion, 30 min of global ischemia (95% reduction of the coronary flow) and 20 min of reperfusion. The control group was equilibrated for 20 min and then aerobically perfused for 50 min. After 20 min of stabilization, ATP and ADP levels and the adenine nucleotide pool were significantly higher in young than aged hearts (15% increase), but no modifications were found between the two age groups after 50 min of aerobic perfusion. Even the energy charge did not change under aerobic conditions. At the end of the ischemic period the levels of ATP and ADP decreased to a similar extent in young and aged hearts. After 20 min of reperfusion the myocardial level of ATP remained lower in comparison to the preischemic and control values in both age groups. At the end of the reperfusion there was a decrease in energy charge and creatine phosphate levels in the aged group in respect to the young group. The concentrations of adenosine, hypoxanthine and xanthine in coronary effluents did not change during ischemia and reperfusion irrespective of the age of the animals. On the contrary, the release of uric acid during ischemia and reperfusion was greater in aged than young hearts (90% increase). Moreover, the level of inosine in perfusates during the ischemic period was significantly lower in the 24-month-old group (30% decrease). These results are in accordance with the increased purine nucleoside phosphorylase activity and the decreased hypoxanthine phosphorybosyl-transferase activity found in the myocardium of the aged vs. young rats at the end of the reperfusion period. These data indicate that in the aged rat hearts, when exposed to ischemic and reperfusion conditions, there is a modification of purine breakdown which leads to a greater production of uric acid in respect to that found in young hearts.

Improvement of long-term preservation of the isolated arrested rat heart by trimetazidine: effects on the energy state and mitochondrial function.

Rat hearts, arrested in situ after intracaval injection of a cardioplegic solution, were preserved for 15 hours at 4 degrees C either by simple immersion or by low-flow (0.3 mL/min) perfusion. After preservation under both conditions, the left ventricular pressure developed by the reperfused hearts reached 8% and 43% of the control value (80 mm Hg), respectively. The addition of trimetazidine (TMZ; 10(-6) M) to the cardioplegic solution induced an improvement in functional recovery (by 2.4 and 1.5, respectively). This effect of TMZ was accompanied by a better energy profile illustrated by a 2-fold increase in the adenosine triphosphate to inorganic phosphate ratio and a reduction of intracellular acidosis as determined by 31P nuclear magnetic resonance spectroscopy. The function of the mitochondria (state 3, reduced nicotinamide-adenine dinucleotide [NADH] formation) isolated from the preserved hearts was significantly depressed in the stored hearts. The addition of TMZ to the cardioplegic solution partially protected oxoglutarate (and succinate) mitochondrial respiration and induced an increase in Ca2+ triggered NADH formation. These results show that the bioenergy status of the myocardial cell in isolated arrested stored rat heart is improved by the presence of TMZ in the preservation solution. Moreover, the experiments demonstrate that this effect includes protection of mitochondrial function and suggest that the drug could exert some control in the Ca2+ regulation of mitochondria.

Effects of increased heart rate and sympathetic tone on intraventricular electrogram morphology.

Electrogram pattern recognition by way of morphologic analysis has been proposed as a technique that may improve discrimination of ventricular tachycardia from sinus rhythm by antitachycardia devices. The potential impact that increases in heart rate and sympathetic tone could have on such techniques, however, has not been previously determined. A comparative study was undertaken to quantify possible changes in ventricular electrogram morphology using correlation waveform, area of difference, and amplitude analyses in 6 patients during atrial overdrive pacing at cycle lengths of 600 and 400 ms (group A), in 13 patients during infusions of physiologic doses of epinephrine (group B), and in 20 patients undergoing infusions of isoproterenol (group C). Four patients were in both groups A and B. A bipolar intraventricular template of cardiac depolarization during sinus rhythm at rest was compared with depolarization during subsequent passages of sinus rhythm at rest and subsequently increased heart rate. In 36 of 39 patients, waveform configuration as assessed by correlation waveform analysis remained relatively stable during atrial overdrive pacing, epinephrine infusion, and isoproterenol infusion when compared with sinus rhythm at rest. The correlation value did not fall below 0.950 in any patient. Area of difference values for the same 36 patients changed by an average of 6 and 37% during atrial overdrive pacing at cycle lengths of 600 and 400 ms intervals, respectively, by 3% during epinephrine infusion, and by 17% during isoproterenol infusion. In these same patients, there was an average change in electrogram amplitude of -1% during atrial overdrive pacing at 600 ms, 26% during pacing at 400 ms, -1% during epinephrine infusion, and 12% during isoproterenol infusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Normal bone marrow karyotype in paroxysmal nocturnal hemoglobinuria--a cooperative European study.

Sixteen patients with paroxysmal nocturnal hemoglobinuria (PNH) from five European centers have been submitted to chromosome analysis. All of them had a normal bone marrow karyotype. The associations between some chromosomally abnormal cases reported in the literature and "typical" PNH or PNH phenomenon during the course of other hematological disorders are discussed.