Effects of one year treatment of vildagliptin added to pioglitazone or glimepiride in poorly controlled type 2 diabetic patients.

The aim of the study was to compare the effects of vildagliptin added to pioglitazone or glimepiride on metabolic and insulin resistance related-indices in poorly controlled type 2 diabetic patients (T2DM). 168 patients with T2DM were randomized to take either pioglitazone 30 mg once a day plus vildagliptin 50 mg twice a day or glimepiride 2 mg 3 times a day plus vildagliptin 50 mg twice a day. We evaluated body weight, body mass index (BMI), glycated hemoglobin (HbA1c), fasting plasma glucose (FPG), postprandial plasma glucose (PPG), fasting plasma insulin (FPI), homeostasis model assessment insulin resistance index (HOMA-IR), homeostasis model assessment beta-cell function index (HOMA-beta), fasting plasma proinsulin (FPPr), proinsulin/fasting plasma insulin ratio (Pr/FPI ratio), adiponectin (ADN), resistin (R), tumor necrosis factor-alpha (TNF-alpha), and high sensitivity C-reactive protein (Hs-CRP) at their baseline values, and after 3, 6, 9, and 12 months of treatment. We observed a similar improvement of HbA1c, FPG, PPG, and Hs-CRP compared to baseline in the 2 groups. Fasting plasma insulin, FPPr, Pr/FPI ratio, R, and TNF-alpha were significantly decreased and ADN was significantly increased with pioglitazone plus vildagliptin, but not with glimepiride plus vildagliptin. HOMA-IR, and HOMA-beta values obtained with pioglitazone plus vildagliptin were significantly better than the values obtained with glimepiride plus vildagliptin. Pioglitazone plus vildagliptin were found to be more effective in preserving beta-cell function, and in reducing insulin resistance, and inflammatory state parameters.

Exenatide versus glibenclamide in patients with diabetes.

BACKGROUND: Incretin-based therapies have provided additional options for the treatment of type 2 diabetes mellitus. The aim of our study was to evaluate the effects of exenatide compared to glibenclamide on body weight, glycemic control, beta-cell function, insulin resistance, and inflammatory state in patients with diabetes. METHODS: One hundred twenty-eight patients with uncontrolled type 2 diabetes mellitus receiving therapy with metformin were randomized to take exenatide 5 microg twice a day or glibenclamide 2.5 mg three times a day and titrated to exenatide 10 microg twice a day or glibenclamide 5 mg three times a day. We evaluated body weight, body mass index (BMI), glycated hemoglobin (HbA(1c)), fasting plasma glucose (FPG), postprandial plasma glucose (PPG), fasting plasma insulin (FPI), homeostasis model assessment insulin resistance (HOMA-IR) index, homeostasis model assessment beta-cell function (HOMA-beta) index, plasma proinsulin (PPr), PPr/FPI ratio, resistin, retinol binding protein-4 (RBP-4), and high-sensitivity C-reactive protein (Hs-CRP) at baseline and after 3, 6, 9, and 12 months. RESULTS: Body weight and BMI decreased with exenatide and increased with glibenclamide. A similar improvement of HbA(1c), FPG, and PPG was obtained in both groups, whereas FPI decreased with exenatide and increased with glibenclamide. The HOMA-IR index decreased and the HOMA-beta index increased with exenatide but not with glibenclamide. A decrease of PPr was reported in both groups, but only glibenclamide decreased the PPr/FPI ratio. Resistin and RBP-4 decreased with exenatide and increased with glibenclamide. A decrease of Hs-CRP was obtained with exenatide, whereas no variations were observed with glibenclamide. CONCLUSIONS: Both exenatide and glibenclamide gave a similar improvement of glycemic control, but only exenatide gave improvements of insulin resistance and beta-cell function, giving also a decrease of body weight and of inflammatory state.

Efficacy and safety of ezetimibe/simvastatin association on non-diabetic and diabetic patients with polygenic hypercholesterolemia or combined hyperlipidemia and previously intolerant to standard statin treatment.

BACKGROUND AND OBJECTIVE: One of the problems associated with reaching the low-density lipoprotein cholesterol (LDL-C) target during statin treatment is the emergence of laboratory or clinical side effects. The aim of our study was to evaluate the prevalence of statin-associated adverse events in diabetic and non-diabetic patients affected by polygenic hypercholesterolemia or combined hyperlipidemia and the efficacy and tolerability of treatment with ezetimibe/simvastatin 10/10 mg/day on the same subjects experiencing the adverse events. METHODS: Consecutively enrollment of patients affected by polygenic hypercholesterolemia or combined hyperlipidemia with or without type 2 diabetes mellitus. Each Centre used any of the available statins on the basis of current clinical judgement and monitored enrolled patients for adverse events during the following 2 years. Those patients with moderate adverse events suspended the current statin therapy for 1 month (washout period), and then were shifted to treatment with ezetimibe/simvastatin 10/10 mg/day and again monitored for adverse events in the following 6 months. We assessed body mass index, glycated haemoglobin, fasting plasma glucose, total cholesterol, LDL-C, high-density lipoprotein cholesterol, triglycerides, alanine aminotransferase, aspartate aminotransferase, creatinine phosphokinase and monitored adverse events such as asthenia and myalgia. RESULTS AND DISCUSSION: All 1170 Caucasian patients affected by polygenic hypercholesterolemia obtained a significant reduction in LDL-C during the observation period (P < 0*05), while those with combined hyperlipidemia also showed a reduction in TG plasma level (P < 0*05) and a significant increase in HDL-C (P < 0*05). Patients affected by polygenic hypercholesterolemia experiencing adverse event under statin treatment obtained a significantly lower reduction than those tolerating the treatment (P < 0*001). The prevalence of adverse events under statin treatment was 4*9% in non-diabetic patients with polygenic hypercholesterolemia, 8*6% in those with combined hyperlipidemia, 7*1% in diabetic patients with polygenic hypercholesterolemia and 7*6% in those with combined hyperlipidemia. Six months after the shift to treatment with ezetimibe/simvastatin 10/10 mg, all patients experienced a significant improvement in LDL-C, TG and HDL-C plasma level. No adverse event was registered during the ezetimibe/simvastatin 10/10 mg treatment period. It seems that previous side effects observed with statins did not re-appear with the administration of ezetimibe/simvastatin 10/10 mg/day. CONCLUSIONS: The efficacy and adverse effect profile of the ezetimibe and simvastatin combination appear to be good for both diabetic and nondiabetic patients, and in both conditions.

Study of the mitochondrial transcription factor A (Tfam) gene in the primate Presbytis cristata.

The mitochondrial transcription factor A (Tfam) is a member of the HMG-box protein family, necessary for both transcription and maintenance of mitochondrial DNA. The gene is structured in seven exons and six introns and it is estimated to span about 10 kb in mouse, human and rat. In addition to the full length mRNA of Tfam, a shorter mRNA isoform lacking exon 5 has been found to be widely distributed in human and rat tissues. Here we present the isolation and characterization of Tfam gene in the primate Presbytis cristata which belongs to the Cercopithecidae family. We have determined the complete CDS sequence, the size of all the six introns, the complete sequences of the three shorter ones (I, III, VI) and the partial sequences of the long introns (II, IV, V). The comparison with other available Tfam sequences from mammals has revealed a high degree of conservation (above 90%) both in CDS and introns. By in situ hybridization (FISH) experiments we have mapped Tfam gene on chromosome 12 which, according to other cytogenetics studies, is the homologous region of chromosome 10, where human Tfam has been mapped. Moreover we have searched for the presence of alternatively spliced isoforms through several approaches, such as RT-PCR and differential hybridization. In Presbytis cristata we have not detected the presence of any spliced isoforms lacking exons; however we have identified one isoform in which part of the intron I is retained in the mRNA. The inclusion of this portion of intron I would originate an early stop codon if translated.

Metabolic variations with oral antidiabetic drugs in patients with Type 2 diabetes: comparison between glimepiride and metformin.

Patients with Type 2 diabetes (T2DM) are at high risk of morbidity and mortality from cardiovascular complications, and hypoglycaemia increases this risk. Furthermore, other metabolic parameters exacerbate cardiovascular risk in these patients. The aim of the study was to compare the metabolic effects of glimepiride and metformin in patients with T2DM. We evaluated 164 patients with T2DM (80 males, 84 females) in a multicentre, randomised, controlled, open, parallel group study comparing glimepiride with metformin. Eighty-one patients (aged 56+/-10 yr) received glimepiride (3+/-1 mg/d); 83 patients (aged 58+/-9 yr) received metformin (2500+/-500 mg/d). Patients had been diagnosed for < or = 6 months; they were non-smokers; had no hypertension or coronary heart disease; were not taking hypolipidaemic drugs, diuretics, beta-blockers or thyroxin; and had normal renal function. Metabolic parameters were measured after 6 and 12 months of treatment. Glimepiride significantly lowered lipoprotein(a) [Lp(a)] and homocysteine levels (HCT) at 6 and 12 months. Both glimepiride and metformin lowered plasminogen activator inhibitor Type 1 (PAI-1) at 12 months and significantly improved levels of glycosylated haemoglobin, fasting plasma glucose and post-prandial plasma glucose after 6 and 12 months. Metformin significantly lowered fasting plasma insulin and postprandial plasma insulin. Glimepiride and metformin also reduced levels of other metabolic parameters in patients with T2DM. In particular, glimepiride significantly reduced HCT, Lp(a), and PAI-1 levels, important metabolic risk factors for atherosclerotic vascular disease. These reductions may be owing to improved glucose metabolism, but it cannot be excluded that these drugs have a direct effect on additional metabolic parameters.

The 25 kDa protein recognizing the rat curved region upstream of the origin of the L-strand replication is the rat homologue of the human mitochondrial transcription factor A.

Mass spectrometry matrix-assisted laser desorption ionization (MALDI) analysis and N-terminus sequencing as well as immunoblotting experiments using human and mouse antibodies have allowed us to identify the 25 kDa protein, previously isolated from rat liver using magnetic beads coated with a rat liver mitochondrial (mt) DNA region upstream of the Ori-L, as the homologue of human mt transcription factor A (mtTFA). We can therefore identify this DNA binding protein as the rat mtTFA. Furthermore, since we previously showed that the 25 kDa protein purified from rat liver was able to bind the curved mtDNA region upstream of the Ori-L as well as the curved mtDNA in the D-loop region, the results here reported lead us to state, for the first time, that mtTFA binds both the curved regions of mtDNA upstream of the two replication origins.

In organello footprinting analysis of rat mitochondrial DNA: protein interaction upstream of the Ori-L.

An in organello footprinting approach has been used to probe a protein-DNA interaction of a nuclear coded 25 kDa protein, previously isolated in our laboratory, that binds "in vitro" a region within the ND2 gene, located upstream of the Ori-L. Footprinting studies with the purine-modifying reagent dimethyl sulfate and the pirimidine-modifying reagent potassium permanganate were carried out in isolated mitochondria from rat liver. Dimethyl sulfate footprinting has allowed the detection of a protein-DNA interaction within the curved ND2 region with contact sites located in both the strands. Potassium permanganate footprinting allowed detection of an adjacent permanganate-reactive region. We hypothesize that the permanganate-reactive region is a single stranded DNA due to a profound helix distortion induced by a 25 kDa protein binding to the nearest region.

Isolation of a 25-kDa protein binding to a curved DNA upstream the origin of the L strand replication in the rat mitochondrial genome.

The presence of a curved DNA sequence in the gene for the NADH-dehydrogenase subunit 2 of rat mitochondrial genome, upstream from the origin of the light strand replication have been demonstrated through theoretical analysis and experimental approaches. Gel retardation assays showed that this structure makes a complex with a protein component extracted from the mitochondrial matrix. The isolation and purification of this protein is reported. With a Sepharose CL-6B and magnetic DNA affinity chromatography a polypeptide was purified to homogeneity having 25-kDa mass as shown by gel electrophoresis. To functionally characterize this protein, its capability to bind to other sequences of the homologous or heterologous DNA and to specific riboprobes was also investigated. A role for this protein as a trans-acting agent required for the expression of the mammalian mitochondrial genome is suggested.

A 67-kDa protein binding to the curved DNA in the main regulatory region of the rat mitochondrial genome.

We have purified, by sequence-specific affinity chromatography, a mitochondrial (mt) matrix protein which binds to the curved DNA located between the replication origin (ori) of the leading strand (ori-H) and the two transcription promoters in the rat mt genome. The protein was characterized by gel electrophoresis as a 67-kDa polypeptide and seems to be involved in the DNA contact on the mt light strand. This protein differs (in the size and location of its DNA-binding site) from other DNA-binding proteins studied so far in animal mt systems. We suggest a role for the 67-kDa protein, assisted by other proteins, in regulating the initiation of leading-strand replication.

[Complications and sequelae of cardiac electrostimulation in children. Our experience with 47 children]. / Complicanze e sequele dell'elettrostimolazione cardiaca in età pediatrica. Nostra esperienza in 47 bambini.

Permanent cardiac pacing is now easily feasible in children and even in small infants, but the long-term results of this procedure are not well known. We analyzed our experience to determine the morbidity of pacing in children. Over the past 10 years, 47 pediatric patients (pts) required pacemaker implantation in our institution. The mean age was 8.3 +/- 4 years (1 day-17 years) and mean body weight was 23 +/- 14 Kg (2.2-60 Kg). 25 pts had heart disease. 40 children had an A-V block (congenital in 22 cases, post-operative in 17 pts, and secondary to a systemic disease in 1 case); 7 pts had a sick sinus syndrome, primitive in 4 and postoperative in 3 cases. The first pacemaker implantation was epicardial in 17 and transvenous in 30 pts. The pacing was single-chamber in 45 pts (VVI 32, VVIr 7, AAI 5, AAIr 1) and dual-chamber in 2 pts (DDD 1, VDD 1). Two newborns, both with a congenital A-V block and severe heart failure, died in the first hours after epicardial pacing. Two other children, both with congenital heart disease, died during follow-up, but the death was not pacemaker-related. Finally, two children were lost to follow-up. The mean follow-up of the 41 remaining pts was 5.2 +/- 3.5 years (4 months-10 years). Twelve children (29%) required 19 implant revisions and the causes were: lead fracture (26%), rising stimulation threshold (26%), growth problems (21%), erosion and/or pocket infection (21%). Revisions were more common in epicardial (52%) than in endocardial (22%) implantation.(ABSTRACT TRUNCATED AT 250 WORDS)

Sequence-dependent DNA curvature: conformational signal present in the main regulatory region of the rat mitochondrial genome.

Theoretical analysis and experimental approaches by gel electrophoresis in retarding conditions allowed us to identify the presence of an intrinsic bending in the D-loop containing region of the rat mitochondrial genome. The curvature was located in the right domain of the sequence analyzed, between the origin of replication of the heavy strand and its promoter. The preliminary evidence of a specific recognition of the bent DNA with mitochondrial matrix proteins suggests a probable role of this DNA conformation in the duplication and/or expression of the mammalian mitochondrial genome.

The complete nucleotide sequence of the Rattus norvegicus mitochondrial genome: cryptic signals revealed by comparative analysis between vertebrates.

This paper reports the nucleotide sequence of rat mitochondrial DNA, only the fourth mammalian mitochondrial genome to be completely sequenced. Extensive comparative studies performed with similar genomes from other organisms revealed a number of interesting features. 1) Messenger RNA genes: the codon strategy is mainly dictated by the base compositional constraints of the corresponding codogenic DNA strand. The usage of the initiation and termination codons follows well-established rules. In general the canonical initiator, ATG, and terminators, TAA and TAG (in rat, only TAA), are always present when there is gene overlapping or when the mRNAs possess untranslated nucleotides at the 5' or 3' ends. 2) Transfer RNA genes: a number of features suggest the peculiar evolutionary behavior of this class of genes and confirm their role in the duplication and rearrangement processes that took place in the evolution of the animal mitochondrial genome. 3) Ribosomal RNA genes: accurate sequence analysis revealed a number of significant examples of complementarity between ribosomal and messenger RNAs. This suggests that they might play an important role in the regulation of mitochondrial translation and transcription mechanisms. The properties revealed by our work shed new light on the organization and evolution of the vertebrate mitochondrial genome and more importantly open up the way to clearly aimed experimental studies of the regulatory mechanisms in mitochondria.

[Role of ambulatory ECG in the diagnostic work of a cardiology division]. / Ruolo dell'ECG dinamico nell'iter diagnostico in una Divisione di Cardiologia.

Holter monitoring may be effected during hospitalization either for clinical research or for high-risk patients or after surgical treatments. In the other cases, if possible, it should be better to effect ambulatory electrocardiographic monitoring in patients engaged in their normal daily activity nevertheless reducing hospital costs. Last year, in our department we effected 2420 Holter monitoring, of which 44% for patients hospitalized in our department, 11% hospitalized in other divisions, 44% for ambulatory patients. Holter monitoring was effected in the 35% of patients to detect arrhythmias, in the 29% for the evaluation of the effect of antiarrhythmic therapy; the 28% of Holter monitoring was recorded for patients recovering from acute infarction. Holter monitoring, associated to the other cardiological screening tests, has a very important rule for diagnosis of arrhythmias or myocardial ischemia, prognostic evaluation of cardiopathic patients (ischemic heart disease, cardiomyopathies, valvular and congenital heart disease), verification of the effects of therapy (PTCA, surgical and antiarrhythmic treatment).

Structural conservation and variation in the D-loop-containing region of vertebrate mitochondrial DNA.

The nucleotide sequences of the D-loop-containing regions of three rat mitochondrial DNAs (mtDNAs), two from the species Rattus norvegicus and one from R. rattus, were determined. Comparisons made among these sequences and with the mouse sequence showed that, on the basis of both base composition and frequency of nucleotide alterations, three domains could be defined within the D-loop-containing region: a central conserved segment, poor in L-strand adenine, flanked by two divergent, adenine-rich regions. Deletions and insertions were found to occur at an unexpectedly high frequency in these sequences and the conserved sequence block called CSB-1 was found not to be intact in the R. rattus sequence. Although in comparisons of more distantly related mtDNAs the D-loop region is the most divergent on the molecule, it does not diverge more than typical protein genes between R. norvegicus and R. rattus, and its central conserved domain appears to be one of the molecule's most conserved regions. The most variable domain borders the tRNAPhe gene and contains the L and H-strand promoters and the 5' terminus for H-strand DNA synthesis. Within this region we have found sequences in all the mtDNAs we have examined, including those of human, two artiodactyls and Xenopus, that are capable of folding into cloverleaf structures. In the other divergent domain of the same mtDNAs, we find sequences capable of assuming similar secondary structural configurations at or near the sites for the termination of D-loop DNA synthesis. The evolutionary preservation of the potential to form such structures despite the high primary-structural divergence of the regions they occur in, suggests the structures are of principal importance for some processes occurring in the D-loop-containing region.

[HLA typing and insulin antibody production in insulin-dependent diabetics]. / Tipizzazione HLA e produzione di anticorpi anti-insulina nel diabetico insulina-dipendente.

The literature of the past ten years shows that the introduction of highly purified heterologous and, lastly, homologous insulins has notably lowered the production of IgG and IgE specific insulin antibodies, but has not succeeded in completely eliminating clinical manifestations of the immune or hyper-immune response to insulin therapy. In particular, insulin allergy with or without lipodystrophy is still seen. Among the factors of insulin immunogenicity, there is a possible genetic control of the immune response in type I diabetes: determining HLA halloantigens (A, B, C, D) might identify specific immune response genes (Ir genes). Initial researches, performed until now almost exclusively upon diabetics treated with conventional heterologous insulin, seem to indicate a positive relationship between haplotype HLA - B15 - DR4 and an elevated immune response, whereas haplotypes HLA - B8 - DR3 and HLA - B18 - DR3 might protect against the formation of anti-insulin antibodies. Antigens D/DR3 and D/DR4 are known to be primitively associated to susceptibility for type I diabetes, whereas antigens B8, B15, B18 are secondarily associated to the rise in frequency of DR3 and DR4 for the "linkage disequilibrium" existing between alleles of B and D loci. The results of HLA typing are presented in 2 groups of insulin-dependent diabetics (ID) followed from an immunological viewpoint during therapy with monocomponent heterologous insulin for over 5 years. The first group is composed of 50 patients with low IgG anti-insulin antibody titers (less than 1 mU/ml, Christiansen: low responders); the second group is made up of 23 patients with high IgG anti-insulin antibody titers (greater than 2.5 mU/ml, Christiansen: high responders) and includes 5 subjects with insulin allergy (associated or not with insulin lipoatrophy) and high levels of insulin specific IgE antibodies. A study of the frequencies of various HLA-B antigens in both groups of patients, in regard to a control group of piemontese population, in relation to the intensity of association (relative risk) and to the statistical importance of frequencies, shows only a possible protective effect of the HLA-B18 phenotype (linkage disequilibrium with HLA - DR3) towards the production of anti-insulin antibodies and hyperimmune clinical manifestations, such as allergy. Reliable conclusions are not possible between low and high responders for the other phenotypes (HLA - B7, B8, B15) commonly implicated. HLA-B12 was noted in 3 of 5 patients with allergy, in 2 cases associated with B8.(ABSTRACT TRUNCATED AT 400 WORDS)

Non-random patterns of nucleotide substitutions and codon strategy in the mammalian mitochondrial genes coding for identified and unidentified reading frames.

The base sequence of large part of the mitochondrial DNA of Wistar rats is presented. The sequence is compared with those of other mammalian mitochondrial DNAs. The nucleotide and amino acid homologies, codon strategy, nature and patterns of substitutions are reported. It results a very high amount of silent substitutions and, in short divergence time, a predominance of transitions on transversions. In both types of substitutions a strong bias in avoiding the use of the G in the third codon position is observed.