A potential role of calpains in sulfonylureas (SUs) -mediated death of human pancreatic cancer cells (1.2B4)

Sulfonylureas (SUs) are suggested to accelerate the pancreatic β-cells mass loss via apoptosis. However, little is known whether calpains mediate this process. The aim of the present study is to evaluate the involvement of calpains in SUs-induced death of human pancreatic cancer (PC) cell line 1.2B4. The cells were exposed to: glibenclamide, glimepiride and gliclazide for 72 h. The expression analysis of caspase-3 (CASP-3), TP53, calpain 1 (CAPN-1), calpain 2 (CAPN-2) and calpain 10 (CAPN-10) was detected using RT-PCR method. Intracellular Ca²⁺ concentrations, CASP-3 activity and total calpain activity were also evaluated. Our results have shown that glibenclamide and glimepiride decrease 1.2B4 cells viability with accompanied increase in intracellular Ca²⁺ concentration and increased expression of apoptosis-related CASP-3 and TP53. Gliclazide did not affect 1.2B4 cell viability and Ca²⁺ concentration, however, it downregulated CASP-3 and upregulated TP53. Interestingly, 50 μM glimepiride increased expression of CAPN-1, CAPN-2 and CAPN-10 whereas 50 μM glibenclamide solely upregulated CAPN-2 expression. We have shown that 10 μM and 50 μM glibenclamide and glimepiride increased the activity of CASP-3, but decreased total calpain activity. Our results suggest that calpains may be involved in glibenclamide- and glimepiride-induced death of PC cells. However, further investigation is required to confirm the engagement of calpains in SUs-mediated death of PC cells, especially studies on protein level of particular isoforms of calpains should be conducted.

The Role of microRNAs in Metabolic Syndrome-Related Oxidative Stress

Oxidative stress (OxS) is the cause and the consequence of metabolic syndrome (MetS), the incidence and economic burden of which is increasing each year. OxS triggers the dysregulation of signaling pathways associated with metabolism and epigenetics, including microRNAs, which are biomarkers of metabolic disorders. In this review, we aimed to summarize the current knowledge regarding the interplay between microRNAs and OxS in MetS and its components. We searched PubMed and Google Scholar to summarize the most relevant studies. Collected data suggested that different sources of OxS (e.g., hyperglycemia, insulin resistance (IR), hyperlipidemia, obesity, proinflammatory cytokines) change the expression of numerous microRNAs in organs involved in the regulation of glucose and lipid metabolism and endothelium. Dysregulated microRNAs either directly or indirectly affect the expression and/or activity of molecules of antioxidative signaling pathways (SIRT1, FOXOs, Keap1/Nrf2) along with effector enzymes (e.g., GPx-1, SOD1/2, HO-1), ROS producers (e.g., NOX4/5), as well as genes of numerous signaling pathways connected with inflammation, insulin sensitivity, and lipid metabolism, thus promoting the progression of metabolic imbalance. MicroRNAs appear to be important epigenetic modifiers in managing the delicate redox balance, mediating either pro- or antioxidant biological impacts. Summarizing, microRNAs may be promising therapeutic targets in ameliorating the repercussions of OxS in MetS.

Life-threatening Anaemia in Patient with Hereditary Haemorrhagic Telangiectasia (Rendu-Osler-Weber Syndrome)

Hereditary haemorrhagic telangiectasia (HHT), also known as Rendu-Osler-Weber syndrome, is a rare autosomal dominant vascular disorder. Patients with HHT may present with a wide spectrum of clinical manifestations from epistaxis to clinically significant arteriovenous malformations (AVM) in the lungs, liver, brain and spine. The diagnosis of HHT is based on clinical criteria. There is a long diagnostic delay of nearly 3 decades since disease onset. The treatment is based on various types of haemostasis. There is ongoing research with potential therapies which may prevent and decrease the severity of epistaxis. Thalidomide may be an effective treatment to decrease the bleeding symptoms of patients with HHT.

Molecular Insight into the Interaction between Epigenetics and Leptin in Metabolic Disorders

Nowadays, it is well-known that the deregulation of epigenetic machinery is a common biological event leading to the development and progression of metabolic disorders. Moreover, the expression level and actions of leptin, a vast adipocytokine regulating energy metabolism, appear to be strongly associated with epigenetics. Therefore, the aim of this review was to summarize the current knowledge of the epigenetic regulation of leptin as well as the leptin-induced epigenetic modifications in metabolic disorders and associated phenomena. The collected data indicated that the deregulation of leptin expression and secretion that occurs during the course of metabolic diseases is underlain by a variation in the level of promoter methylation, the occurrence of histone modifications, along with miRNA interference. Furthermore, leptin was proven to epigenetically regulate several miRNAs and affect the activity of the histone deacetylases. These epigenetic modifications were observed in obesity, gestational diabetes, metabolic syndrome and concerned various molecular processes like glucose metabolism, insulin sensitivity, liver fibrosis, obesity-related carcinogenesis, adipogenesis or fetal/early postnatal programming. Moreover, the circulating miRNA profiles were associated with the plasma leptin level in metabolic syndrome, and miRNAs were found to be involved in hypothalamic leptin sensitivity. In summary, the evidence suggests that leptin is both a target and a mediator of epigenetic changes that develop in numerous tissues during metabolic disorders.

Hyperglycemia Affects miRNAs Expression Pattern during Adipogenesis of Human Visceral Adipocytes-Is Memorization Involved?

microRNAs are increasingly analyzed in adipogenesis, whose deregulation, especially visceral, contributes to the development of diabetes. Hyperglycemia is known to affect cells while occurring acutely and chronically. Therefore, we aimed to evaluate the effect of hyperglycemia on human visceral pre/adipocytes from the perspective of microRNAs. The relative expression of 78 microRNAs was determined by TaqMan Low Density Arrays at three stages of HPA-v adipogenesis conducted under normoglycemia, chronic, and intermittent hyperglycemia (30 mM). Hierarchical clustering/Pearson correlation revealed the relationship between various microRNAs' expression profiles, while functional analysis identified the genes and signaling pathways regulated by differentially expressed microRNAs. Hyperglycemia affected microRNAs' expression patterns during adipogenesis, and at the stage of pre-adipocytes, differentiated and matured adipocytes compared to normoglycemia. Interestingly, the changes that were evoked upon hyperglycemic exposure during one adipogenesis stage resembled those observed upon chronic hyperglycemia. At least 15 microRNAs were modulated during normoglycemic and/or hyperglycemic adipogenesis and/or upon intermittent/chronic hyperglycemia. Bioinformatics analysis revealed the involvement of these microRNAs in cell cycles, lipid metabolism, ECM⁻receptor interaction, oxidative stress, signaling of insulin, MAPK, TGF-β, p53, and more. The obtained data suggests that visceral pre/adipocytes exposed to chronic/intermittent hyperglycemia develop a microRNAs' expression pattern, which may contribute to further visceral dysfunction, the progression of diabetic phenotype, and diabetic complications possibly involving "epi"-memory.

Tumour protein 53 is linked with type 2 diabetes mellitus

BACKGROUND & OBJECTIVES

Tumour protein p53 (TP53) is a stress sensitive transcription factor responsible for the control of cell survival and death to prevent from tumour formation. In vitro and animal studies have indicated that TP53 also responds to metabolic changes and influences metabolic pathways. This study was undertaken to determine the serum level of TP53 and its correlations with clinical and biochemical parameters in type 2 diabetes mellitus (T2DM) patients in comparison to non-diabetic control individuals.

METHODS

An observational study was conducted between December 2009 and November 2013 to evaluate TP53 serum level using ELISA. Cases (n=225) were defined as patients who were diagnosed with T2DM. Non-diabetic controls (n=255) were matched by age and sex. Multivariable modelling using logistic regression examined associations between clinical characteristics and TP53 level or T2DM predication was performed.

RESULTS

Serum TP53 level was significantly higher in T2DM patients as compared to non-diabetic healthy controls (1.69 vs 2.07 ng/ml, P<0.001). In T2DM patients, the level of TP53 increased with the age, duration of diabetes and waist-to-hip ratio (WHR) value. A logistic regression analysis revealed that increased serum TP53 level was significantly associated with family history of diabetes, age and WHR. Moreover, TP53, triglyceride and body mass index could be used to predict T2DM.

INTERPRETATION & CONCLUSIONS

Our results suggest that TP53 may be linked with T2DM. The fluctuations of serum TP53 level may reflect metabolic and oxidative stress associated with chronic hyperglycaemia. Further studies need to be done to confirm these findings.

Analysis of oxidative DNA damage and its repair in Polish patients with diabetes mellitus type 2: Role in pathogenesis of diabetic neuropathy

PURPOSE

Distal symmetric polyneuropathy (DSPN) is common complication of type 2 diabetes (T2DM). In this work we investigated the role of oxidative damage in connection with particular polymorphisms of DNA repair genes and their repair capacity.

MATERIAL/METHODS

Materials constitute the peripheral blood of patients with T2DM with and without DSPN and control subjects without disturbance of the carbohydrate fraction. The study of gene polymorphisms which products take part in base excision repair (BER) pathway: 726 Val/Ala adenosine diphosphate ribosyl transferase (ADPRT), 324 His/Glu MutYhomolog (MUTYH) and 148 Asp/Glu human apurinic/apyrimidinic endonuclease (APE) was carried out using restriction fragment length polymorphism polymerase chain reaction (PCR-RFLP) method. The study of DNA damage induced by hydrogen peroxide and the efficiency of their repair was carried out using comet assay.

RESULTS

None of the 3 polymorphisms were associated with the risk of DSPN. However, in group of patients together with T2DM and T2DM/DSPN 726 Ala ADPRT allele was significantly susceptible to increased risk of T2DM (OR=1.59; 95% CI: 1.08-2.36). Investigation of DNA damage and repair revealed that T2DM patients have decreased ability to DNA repair. This capacity even drops down in the group of T2DM/DSPN patients compared to subjects with diabetes alone. ADPRT and APE polymorphisms were significantly associated with higher DNA damages (P<0.05) in heterozygous and mutant homozygous in correlation to homozygous wild type, but for MUTYH polymorphism relation was not confirmed.

CONCLUSIONS

Pathogenesis of T2DM and development of DSPN may be related to oxidative stress connected with BER gene polymorphisms.

Metformin in cancer prevention and therapy

The prevalence of diabetes is dramatically increasing worldwide. The results of numerous epidemiological studies indicate that diabetic population is not only at increased risk of cardiovascular complications, but also at substantially higher risk of many forms of malignancies. The use of metformin, the most commonly prescribed drug for type 2 diabetes, was repeatedly associated with the decreased risk of the occurrence of various types of cancers, especially of pancreas and colon and hepatocellular carcinoma. This observation was also confirmed by the results of numerous meta-analyses. There are however, several unanswered questions regarding the exact mechanism of the anticancer effect of metformin as well as its activity against various types of cancer both in diabetic and nondiabetic populations. In the present work we discuss the proposed mechanism(s) of anticancer effect of metformin and preclinical and clinical data suggesting its anticancer effect in different populations.

Heart failure in the diabetic population - pathophysiology, diagnosis and management

Evidence from clinical trials repeatedly confirms the association of diabetes with heart failure, independent of hypertension, atherosclerosis, coronary artery disease and valvular heart disease. However, the importance of coexistence of diabetes and heart failure is not universally recognized, despite the fact that it may significantly contribute to morbidity and mortality of the diabetic population. It seems that prevention of heart failure, early diagnosis, and appropriate management could improve the outcome. Unfortunately, the etiology of heart failure in diabetic patients is still to be elucidated. It is multifactorial in nature and several cellular, molecular and metabolic factors are implicated. Additionally, there are still no definite guidelines on either the diagnosis and treatment of heart failure in diabetic patients or on the therapy of diabetes in subjects with heart failure. This review focuses on the pathophysiology, diagnosis, and prevention of heart failure in the diabetic population as well as management of both comorbidities.

Advances in the diagnosis and management of diabetic distal symmetric polyneuropathy

Distal symmetric polyneuropathy (DSPN) is the most common chronic complication of diabetes mellitus. The pathogenesis of DSPN is not fully elucidated, but it is certainly multifactorial in nature and attributable to metabolic and microvessel disorders related to chronic hyperglycemia, diabetes duration, and several cardiovascular risk factors. Early diagnosis and appropriate management are extremely important, since up to 50% of DSPN cases may be asymptomatic, and patients are unaware of foot injury leading to foot ulcers and amputation. Simple, validated tests such as the Neuropathy Disability Score and/or Vibration Perception Threshold may be used to diagnose DSPN. Similarly, neurological dysfunction screening questionnaires should be used to assess the quality and severity of DSPN symptoms. Using both methods enables prediction of the prognosis of diabetic patients with DSPN. No causative treatment of DSPN is known, but the results of clinical trials indicate that several treatment options are highly effective in symptomatic treatment of painful DSPN. The appropriate treatment of DSPN may improve the outcome, preventing or delaying the development of numerous diabetic complications.

Relationship between ultrasound features of nonalcoholic fatty liver disease and cardiometabolic risk factors in patients with newly diagnosed type 2 diabetes

INTRODUCTION

 It is suggested that nonalcoholic fatty liver disease (NAFLD) correlates with cardiometabolic risk factors in patients with newly diagnosed type 2 diabetes.

OBJECTIVES

 The aim of this study was to evaluate the prevalence of ultrasound features of NAFLD in patients with newly diagnosed type 2 diabetes and their relationship with cardiometabolic risk factors.

PATIENTS AND METHODS

 The study included 100 consecutive patients (mean age, 55.64 ±13.42 years) with newly diagnosed type 2 diabetes, without other causes of hepatosteatosis. In each patient, medical history was taken, physical and abdominal ultrasound examinations were performed, and anthropometric and biochemical parameters were measured. Based on the results of an ultrasound examination, patients were assigned to 2 groups: with (n = 71) and without (n = 29) NAFLD.

RESULTS

 NAFLD was present in more than 70% of the patients with diabetes. In patients with NAFLD, significantly higher mean values of body weight, waist and hip circumferences, body mass index, liver enzyme activity, serum C‑reactive protein, total cholesterol, and triglycerides and significantly lower levels of high‑density lipoprotein (HDL) cholesterol were observed. There were no significant differences in the parameters of glycemic control between the groups. A correlation was observed between ultrasound features of NAFLD and some cardiovascular risk factors. Increased waist circumference and serum γ‑glutamyltransferase level and decreased HDL‑cholesterol levels were shown to be independent risk factors of NAFLD.

CONCLUSIONS

 Liver ultrasound should be performed in every patient with newly diagnosed type 2 diabetes. Our findings indicate a relationship between NAFLD and multiple cardiometabolic risk factors. The measurement of selected biochemical and anthropometric parameters may be used to assess the risk of NAFLD in this patient group.

Evaluation of oxidative stress markers in pathogenesis of diabetic neuropathy

Experimental evidences suggest that hyperglycaemia-induced overproduction of reactive oxygen species and subsequent damage to proteins, lipids and DNA may play a key role in the development of distal symmetric polyneuropathy (DSPN)—the most common complication of diabetes mellitus. The study population consisted of 51 individuals aged 52–82 years classified into 3 groups: 16 patients diagnosed with type 2 diabetes mellitus (T2DM) with DSPN, 16 T2DM patients without DSPN and 19 control subjects without diabetes and neuropathy. The study was conducted to determine the activity of antioxidant enzymes: catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPX) and total antioxidant status (TAS) in the examined groups. An alkaline comet assay was used to determine the extent of DNA damage of oxidized purines as glicosylo-formamidoglicosylase (Fpg) sites, and oxidized pyrimidines as endonuclease III (Nth) sites. A significant decrease of SOD (P < 0.05), GPX (P < 0.05) and nonsignificant decrease of CAT (P > 0.05), and TAS status (P > 0.05) were seen in T2DM patients with neuropathy compared to T2DM patients as well as controls. T2DM patients with or without neuropathy revealed significantly lower (P < 0.05) plasma concentration of nitrous oxide compared to the control subjects. Endogenous level of oxidative DNA damage in T2DM patients with DSPN was significantly higher compared both to the controls and T2DM patients without DSPN (P < 0.001). Moreover, lymphocytes isolated from T2DM patients with DSPN were more susceptible to oxidative DNA lesions induced by hydrogen peroxide than from T2DM patients without DSPN (P < 0.001). Our results confirm hypothesis that oxidative stress may play a substantial role in the development and progression of diabetic distal symmetric polyneuropathy.

Perspectives on the use of melatonin to reduce cytotoxic and genotoxic effects of methacrylate-based dental materials

Melatonin (5-methoxy-N-acetyltryptamine), an indoleamine produced in the pineal gland and many other organs, displays a wide spectrum of protective effects against cell injury of various origins. Contemporary dental restorative materials mainly consist of methacrylate polymers with some additives. However, because of the incompleteness of polymerization process in situ as well as mechanical shearing and enzymatic degradation, methacrylate monomers are released from the restoration into the oral cavity and the pulp, from where they gain access to other tissues and organs. Such monomers have displayed toxic properties in many in vivo and in vitro studies, including cytotoxicity and genotoxicity and a considerable portion of these effects is underlined by the oxidative action of these compounds. As melatonin shows biocompatibility with the oral cavity and displays antioxidative properties, it may be considered as a protective agent against harmful effects of methacrylate monomers derived from dental restorations. Melatonin decreases cytotoxic and genotoxic effects of methacrylate monomers used in dentistry, and it does not influence the bond strength of dental composites. This opens a new possible application of melatonin to improve properties of biomaterials used in dentistry.

Cytotoxicity and genotoxicity of capecitabine in head and neck cancer and normal cells

The interaction between a chemical and a cell may strongly depend on whether this cell is normal or pathological. Side effects of anticancer drugs may sometimes overcome their benefit action, so it is important to investigate their effect in both the target and normal cells. Capecitabine (Xeloda, CAP), a prodrug of 5-fluorouracil, is mainly used in colon cancer, but little is known about its action in head and neck cancer. We compared the cyto- and genotoxicity of CAP in head and neck HTB-43 cells and normal human lymphocytes by comet assay and flow cytometry. CAP at concentration up to 50 μM significantly decreased the viability of the cancer cells, whereas it did not affect normal lymphocytes. The drug did not interact with isolated plasmid DNA, but it damaged DNA in both cancer and normal cells. However, the extent of the damage in the former was much higher than in the latter. CAP induced apoptosis in the cancer cells, but not in normal lymphocytes. Pre-treatment of the cells with the nitrone spin traps α-(4-pyridil-1-oxide)-N-tert-butylnitrone and N-tert-butyl-α-phenylnitrone decreased the extent of CAP induced DNA damage, suggesting that free radicals may be involved in the formation of DNA lesions induced by CAP. The drug evoked an increase in the G0/G1 cell population accompanied by a decrease in the S cell population. CAP may evoke a pronounced cyto- and genotoxic effects in head and neck cancer cells, whereas it may or may not induce such effects in normal cells to far lesser extent.

Polymorphisms of the DNA repair genes XRCC1 and ERCC4 are not associated with smoking- and drinking-dependent larynx cancer in a Polish population

BACKGROUND

Tobacco smoking and alcohol drinking generate oxidative DNA damage and may contribute to larynx carcinogenesis. The X-ray repair cross complementing 1 (XRCC1) and excision repair cross-complementing rodent repair deficiency, complementation group 4 (ERCC4(XPF)) genes are important components of DNA excision repair systems, which repair DNA damage induced by various factors, including tobacco smoking and alcohol.

AIM

To investigate the association between the genotypes of the XRCC1-Arg399Gln (rs25487) and ERCC4-Arg415Gln (rs1800067) polymorphisms and smoking- and drinking-related larynx cancer in a Polish population.

METHODS

The polymorphisms were determined by PCR-RFLP method in 253 patients with squamous cell carcinoma of the larynx and 253 sex- and age-matched controls.

RESULTS

We did not find any association between the investigated polymorphisms and larynx carcinoma, dependent on either smoking or drinking status. No association was found between these polymorphisms and larynx cancer grade, stage or age at diagnosis.

CONCLUSIONS

The results indicated that Arg399Gln polymorphism of XRCC1 gene and Arg415Gln polymorphism of ERCC4 gene may not be associated with smoking- and drinking-related larynx cancer in Polish population.

Effect of gliclazide on nucleotide excision repair (NER) and non-homologous DNA end joining (NHEJ) in normal and cancer cells

The results of clinical studies revealed that gliclazide may reduce the risk of cancer in type 2 diabetic patients (T2DM), although the mechanism of possible protective effect is not sufficiently explored. The increased level of DNA damage and impaired DNA repair system in diabetes mellitus may play a substantial role in neoplastic transformation. Recently, we have demonstrated that gliclazide protected DNA against damage introduced by the oxidative stress, but its action on the DNA repair mechanisms is unclear. Therefore, the aim of this study was to assess whether gliclazide has any effect on the DNA repair pathways, e.g. nucleotide excision repair (NER) and non-homologous end joining (NHEJ). NER activity was assessed in the extract of human lymphocytes and pancreatic cancer cells (PANC-1) treated or not with gliclazide by use of an UV-irradiated plasmid as a substrate and by quantitative PCR performed to evaluate the efficacy of the removal of UV-induced lesions from the p53 gene by intact cells. The efficacy of NHEJ pathway was examined by a simple and rapid in vitro assay based on fluorescent detection of repair products. We did not observe significant differences between the efficiency of NER and NHEJ for extracts of lymphocytes alone and lymphocytes treated with gliclazide. Contrary, gliclazide increased the efficacy of NER (46.0% vs. 84.0%, p<0.01) and NHEJ (58.0% vs. 66.0%, p<0.05) in PANC-1 cells. In conclusion, the present study showed that gliclazide did not affect NER and NHEJ in human normal cells, but it may stimulate DNA repair in cancer cells.

The role of "metabolic memory" in the natural history of diabetes mellitus

There is growing evidence that early, intensive treatment of new-onset diabetes mellitus aimed at tight glucose control reduces the risk of micro- and macrovascular complications. Metabolic memory is a term used to describe beneficial effects of immediate intensive treatment of hyperglycemia and the observation that they are maintained for many years, regardless of glycemia in the later course of diabetes. This phenomenon was first observed in preclinical studies and was later confirmed in large clinical trials. It has been suggested that early glycemia normalization can halt hyperglycemia-induced pathological processes associated with enhanced oxidative stress and glycation of cellular proteins and lipids. The phenomenon of metabolic memory suggests that antioxidants and agents degrading advanced glycation end products in addition to strict hypoglycemic treatment can be used to prevent chronic diabetic complications.

Association between polymorphisms of the DNA repair genes XRCC1 and hOGG1 and type 2 diabetes mellitus in the Polish population

INTRODUCTION

Elevated oxidative stress in type 2 diabetic patients leads to the accumulation of DNA damage and possibly acceleration of diabetic complications. Numerous studies indicate that diabetic patients may display impaired DNA repair compared to healthy subjects.

OBJECTIVES

The aim of the study was to compare the distribution of genotypes of DNA repair genes between type 2 diabetic patients and non-diabetic subjects.

PATIENTS AND METHODS

Polymerase chain reaction-based restriction fragment length polymorphism was used to determine the distribution of genotypes and frequency of alleles of polymorphisms of base excision repair genes, including the Arg399Gln polymorphism of the XRCC1 gene and Ser326Cys in the hOGG1 gene. The study population included 195 subjects, including 94 with type 2 diabetes mellitus and 101 with normal glucose metabolism. All study participants were Caucasian and inhabited the city of Łódź, Poland.

RESULTS

The frequency of the Gln allele in XRCC1 gene (41% vs. 47%, odds ratio [OR] 0.80, CI 0.54-1.19) and Cys allele in hOGG1 gene (19% vs. 18%, OR 1.09, CI 0.65-1.82) did not differ significantly between diabetic patients and subjects with normal glucose metabolism. Linkage analysis revealed that the Arg/Gln-Ser/Ser combination of genotypes of XRCC1 and hOGG1, respectively (not associated with a decreased activity of both genes) occurs more commonly in type 2 diabetic patients.

CONCLUSIONS

The results of our study suggest no association between decreased activity of the examined DNA repair genes and type 2 diabetes mellitus in the studied population.

Gene polymorphisms and antigen levels of matrix metalloproteinase-1 in type 2 diabetes mellitus coexisting with coronary heart disease

BACKGROUND AND AIM

Diabetes mellitus is a major risk factor for coronary heart disease (CHD). Matrix metalloproteinases (MMPs) can play a pivotal role in the remodelling of extracellular matrix associated with the development of atherosclerosis. Therefore, the aim of the study was to compare the distribution of genotypes and frequency of alleles of two polymorphisms of the MMP-1 gene promoter, an A/G substitution and a 1G/2G insertion, in correlation with antigen levels of matrix metalloproteinase-1 (MMP-1) in type 2 diabetic patients with or without CHD as well as individuals with normal glucose level without CHD.

METHODS

Genotypes of 115 patients with type 2 diabetes mellitus (T2DM) and a subpopulation of 66 patients with coexisting CHD as well as 120 non-diabetic control subjects were determined by PCR-based restriction fragment length polymorphism (PCR-RFLP).

RESULTS

We demonstrated that antigen levels of MMP-1 in the serum of diabetic patients were significantly higher than those of individuals with normal glucose metabolism (p <0.05). Elevated levels of MMP-1 positively correlated with CHD occurrence in T2DM patients (p <0.01). The distribution of genotypes revealed higher frequency of the 2G/2G polymorphism variant in diabetic patients with CHD [OR 5.76, 95% CI (1.24; 26.87)], thus suggesting its strong association with high level of MMP-1. In T2DM patients with coexisting CHD, a higher frequency of the 2G allele of 1G/2G [OR 1.74, CI 95% (1.01; 2.99)] and the G allele of A/G polymorphism [OR 2.15, 95% CI (1.22; 3.80)] was also found.

CONCLUSION

Our results suggest that type 2 diabetes mellitus is linked with elevated blood level of MMP-1, and polymorphisms of the promoter region of its gene might be associated with CHD.

The Trp64Arg β3-Adrenergic Receptor Amino-Acid Variant is not Associated with Overweight and Type 2 Diabetes Mellitus in Polish Population

The Trp64Arg amino-acid variant of the beta3 adrenoreceptor gene may be associated with a genetic predisposition to human obesity and related disorders, including type 2 diabetes mellitus. This relationship has been reported in various ethnic groups, however it was not extensively studied in Polish population. Therefore, the aim of the study was to investigate the association of Trp64Arg polymorphism of the beta3 adrenergic receptor gene with overweight and type 2 diabetes mellitus in polish subjects. The Trp64Arg polymorphism was determined by PCR-based MspI restriction fragment length polymorphism (PCR-RFLP). The study population consisted of 358 subjects, among whom 200 were diagnosed as overweight (BMI > 27 kg/m (2)). Among overweight subjects 111 presented with type 2 diabetes mellitus and 89 with normal glucose metabolism. All study participants were unrelated Caucasians and inhabited the city of Lodz, Poland. The frequency of the Arg allele did not differ significantly between overweight and normal weight patients (13 % vs. 11 %, OR 1.17, CI 0.74 - 1.85). The same applied to overweight diabetic patients vs. overweight patients without diabetes mellitus (13 % vs. 13 %, OR 0.97, CI 0.54 - 1.76). The obtained results suggest no association between Trp64Arg polymorphism of the beta3-AR gene and the incidence of overweight and type 2 diabetes mellitus in Polish population.

DNA damage and repair in type 2 diabetes mellitus

DNA damage may be associated with type 2 diabetes mellitus (T2DM) and its complications mainly through oxidative stress. Little is known about DNA repair disturbances potentially contributing to the overall extent of DNA damage in T2DM, which, in turn, may be linked with genomic instability resulting in cancer. To assess whether DNA repair may be perturbed in 2DM we determined: (1) the level of endogenous basal DNA damage, this means damage recognized in the alkaline comet assay (DNA strand breaks and alkali labile sites) as well as endogenous oxidative and alkylative DNA damage (2) the sensitivity to DNA-damaging agents hydrogen peroxide and doxorubicin and the efficacy of removing of DNA damage induced by these agents in peripheral blood lymphocytes of T2DM patients and healthy individuals. The level of DNA damage and the kinetics of DNA repair was evaluated by the alkaline single cell gel electrophoresis (comet assay). Oxidative and alkylative DNA damage were assayed with the use of DNA repair enzymes endonuclease III (Endo III) and formamidopyrimidine-DNA glycosylase (Fpg), recognizing oxidized DNA bases and 3-methyladenine-DNA glycosylase II (AlkA) recognizing alkylated bases. The levels of basal endogenous and oxidative DNA damage in diabetes patients were higher than in control subjects. There was no difference between the level of alkylative DNA in the patients and the controls. Diabetes patients displayed higher susceptibility to hydrogen peroxide and doxorubicin and decreased efficacy of repairing DNA damage induced by these agents than healthy controls. Our results suggest that type 2 diabetes mellitus may be associated not only with the elevated level of oxidative DNA damage but also with the increased susceptibility to mutagens and the decreased efficacy of DNA repair. These features may contribute to a link between diabetes and cancer and metrics of DNA damage and repair, measured by the comet assay, may be markers of risk of cancer in diabetes.

Effects of indomethacin on hemodynamic parameters after intravenous administration of propranolol and enalaprilat in rabbits

The aim of the present study was to establish the effect of intravenous administration of indomethacin (10 mg/kg), potent inhibitor of prostaglandin synthesis, on hemodynamic parametrs after intravenous administration of propranolol (0.3 mg/kg) and enalaprilat (0.5 mg/kg) in rabbits. The following parameters were estimated: mean arterial blood pressure, heart rate, cardiac output and total peripheral resistance. Blood pressure was measured directly in the carotid artery, heart rate was counted according to ECG, cardiac output and total peripheral resistance were calculated using the method of human 125J albumin dilution. For statistical analysis, the average change in the examined parametres was calculated. Indomethacin significantly increased mean arterial pressure without altering other hemodynamic parameters. Combined intravenous administration of indomethacin with enalaprilat or propranolol abolished hypotensive effect of both drugs. Indomethacin magnified the effect of propranolol on total peripheral resistance and abolished the effect of enalaprilat on this parameter. Co-administration of indomethacin with propranolol or enalaprilat did not influence significantly heart rate and cardiac output in comparison with the effect of both antihypertensive drugs alone. This may indicate the predominant role of the influence of indomethacin on vascular tone in the observed interaction.

The importance of impedance cardiography in monitoring cardiac function in patients with hematological malignancies

Cardiac function was monitored by means of impedance cardiography in the early phase of chemotherapy in 30 patients with hematological malignancies. The patients were divided into two groups according to whether or not they revealed cardiac risk factors (age > 65, coronary heart disease, cardiac failure, hypertension, diabetes mellitus or prior mediastinal irradiation). It was found that the mean values of cardiac and stroke indices before chemotherapy were significantly lower in patients with cardiac risk factors. It was also noted that the mean values of these indices in both groups did not change significantly after anticancer treatment. However, in two patients a significant decrease of cardiac indices was observed. On the other hand, in several patients an increase of cardiac and stroke indices was recorded. It seems that careful measurements of cardiac function in cancer patients by impedance cardiography enable to analyze the influence of anticancer drugs upon the cardiovascular system. The results of these measurements may be used for the individualization of cancer therapy.