Effect of trimetazidine on xanthine oxidoreductase expression in rat kidney with ischemia--reperfusion injury

Ischemia/reperfusion (I/R) injury is often responsible for delayed graft function after transplantation. Trimetazidine (TMZ) is an anti-ischemic and antioxidant agent used to protect grafts from I/R injury. With the supply of molecular oxygen upon reperfusion of ischemic tissues, xanthine oxidoreductase (XOR) metabolizes xanthine and hypoxanthine to uric acid and free radicals are generated. The aim of the study was to examine the effect of TMZ on XOR expression in rat kidney with I/R injury. The study was carried out on Wistar rats divided into two groups: animals treated with TMZ and control group receiving placebo. TMZ (10 mg/kg/day) was administered for 30 days. There were no significant differences in XOR expression in kidneys without ischemia between rats treated with TMZ and control group, whereas the XOR expression in kidneys with ischemia was significantly decreased in rats treated with TMZ as compared with control animals. The XOR expression in ischemic kidney was significantly lower in comparison with kidney without ischemia in the group treated with TMZ. We suggest that the decrease in xanthine oxidoreductase expression is one of the beneficial mechanisms of TMZ on I/R injury, preventing the degradation of purine nucleotides during the oxidation of hypoxanthine to xanthine and uric acid and formation of free radicals.

Metabolism in adipose tissue in response to citalopram and trimipramine treatment--an in situ microdialysis study

The intake of antidepressants is often accompanied by weight gain. Antidepressants may influence lipid and carbohydrate metabolism that can result in metabolic changes and obesity. We investigated the effect of citalopram and trimipramine on interstitial glycerol, glucose and lactate concentration and blood flow in subcutaneous adipose tissue of obese subjects by means of the microdialysis technique. In addition, the effect of stimulation with norepinephrine on metabolic response was investigated. Each subject was compared to a control subject matched for BMI and age. Each group comprised 10 subjects. Circulating plasma triglyceride concentrations were higher in drug-treated groups. In subcutaneous adipose tissue, microdialysis experiments revealed a higher and prolonged glycerol release in the presence of norepinephrine, but not under basal conditions. In citalopram treated subjects, basal glucose and lactate concentrations were higher compared with controls or with the trimipramine treated group. Local administration of norepinephrine induced a decrease in glucose levels and an increase in lactate levels, but without significant differences between groups. Local adipose tissue blood flow decreased in control groups following norepinephrine application, but remained constant in the antidepressant groups. In conclusion, citalopram and trimipramine affected glucose and lipid metabolism in adipose tissue and resulted in enhanced release of glycerol and free fatty acids into the circulation.

[A 40-year-old female patient with seronegative autoimmune hepatitis following a newly acquired hepatitis B infection]

We report the case of a 40-year-old female patient admitted at our clinic because of recent onset jaundice and elevated transaminases. Two months before admission the patient had unprotected sexual contact with a potential hepatitis B-infected man. Virological screening performed in our clinic revealed IgM antibodies against hepatitis B virus core protein (anti-HBc-IgM) and elevated HBV-DNA. Our first diagnosis was an acute hepatitis B virus infection. During her stay at our clinic the patient achieved HBe seroconversion and a loss of HBV-DNA. Nevertheless the transaminases remained high and jaundice persisted. The histological examination of the liver biopsy showed interface hepatitis with plasma cells as the characteristic signs of autoimmune hepatitis. On that basis we started an immunosuppressive therapy with prednisolone in parallel with a prophylactic lamivudine therapy and after two weeks there was a complete resolution of jaundice and a normalisation of transaminases. In conclusion, we present a rare case report of an autoimmune hepatitis as a result a newly acquired hepatitis B infection. This case report highlights the relationship between viral infection and autoimmunity within the liver.

Second messenger regulation of mRNA for corticotropin-releasing factor

An understanding of how second messengers and their ligands are coupled to CRF gene activation is necessary if we are to understand the regulation of the CRF gene in physiological and pathological states. The protein kinase A, protein kinase C and glucocorticoid second messenger systems mediate most of the regulation of the CRF gene. In in vitro systems, CRF gene expression is stimulated 20-30-fold by activation of either the protein kinase A or the protein kinase C system. Glucocorticoid is able to inhibit stimulation via both pathways, but appears to be more effective in repressing activation mediated by protein kinase C. Glucocorticoid negative regulation requires the presence of glucocorticoid receptor possessing an intact DNA-binding domain, suggesting that this effect involves binding of the receptor to the CRF promoter. These in vitro studies should serve to guide investigators towards the possible mechanisms underlying CRF gene regulation in vivo.

Conjugated linoleic acids can change phagocytosis of human monocytes/macrophages by reduction in Cox-2 expression

Prostaglandin E2 produced endogenously (by cyclooxygenases) can regulate macrophage phagocytosis. Cyclooxygenase activity reduction (mainly through inhibition of inducible Cox-2) can induce PGE2 synthesis depression and can activate the phagocytosis process. There are no reports in the literature explaining whether conjugated linoleic acid dienes (trans-10, cis-12 CLA and cis-9, trans-11 CLA) modify the phagocytic activity of human macrophages. For the purpose of this study, monocytes were isolated from venous blood, incubated for 7 days with 30 microM CLAs, and then (in some experiments) LPS (1 microg/mL) was added to the medium. Subsequently, monocyte/macrophage phagocytosis, NF-kappaB transcription factor activity, Cox-2 and PPARgamma mRNA expression (and the amounts of Cox-2 and PPARgamma proteins) and PGE2 synthesis were determined. Both CLA isomers increased macrophage phagocytosis through inhibition of Cox-2 expression (might by inactivation the NF-kappaB pathway). The inhibition of mRNA Cox-2 expression contributed (particularly with respect to trans-10, cis-12 CLA) to a decrease in protein Cox-2 synthesis and to reduction of prostaglandin E2 content in the cell. The inhibition of PGE2 synthesis (by CLA treatment) enhanced the phagocytosis process in macrophages.

Thirty-eight-negative kinase 1 (TNK1) facilitates TNFα-induced apoptosis by blocking NF-κB activation

Thirty-eight-negative kinase 1 (TNK1) is a member of the ACK-family of nonreceptor tyrosine kinases and was originally cloned from CD34+/Lin-/CD38-hematopoietic stem/progenitor cells. The signaling pathways induced by TNK1 are largely unknown. Here, we report that expression and consequent activation of TNK1 enables tumor necrosis factor alpha (TNFalpha)-induced apoptosis by selectively inhibiting TNFalpha-induced activation of nuclear factor-kappaB (NF-kappaB). TNK1 has no effect on NF-kappaB DNA binding or the composition of the NF-kappaB complex; however, the kinase markedly prevents TNFalpha-induced NF-kappaB transactivation. TNK1 therefore acts as a novel molecular switch that can determine the properties of TNFalpha signaling and therefore cell death.

[Reflux-associated nutcracker oesophagus in a 49-year-old patient with non-cardiac chest pain (NCCP)]

A 49-year-old woman was admitted to our department because of intermittent left-sided chest pain for the past 2 years. The patient reported an increasing frequency and duration of the symptoms which were independent from food intake, medication or physical exercises. A cardiac cause of the chest pain was excluded before admittance to our hospital. The initially performed upper endoscopy revealed a small oesophageal hiatal hernia but no signs of acute or chronic inflammation. Basal oesophageal manometry and pH monitoring confirmed the presence of a nutcracker oesophagus, defined by high-amplitude contractions of the distal oesophagus, in combination with a gastro-oesophageal reflux disease. The patient was treated with high-dose pantoprazole for 8 weeks before re-examination. Interestingly, the symptoms completely disappeared upon medication and the relief of the chest pain was accompanied by normalisation of the nutcracker oesophagus pattern. Thus, our observation provides evidence for a causative role of acid reflux in the pathophysiology of the nutcracker oesophagus and, in addition, suggests that effective acid suppression might be a useful therapeutic tool to deal with this painful motility disorder of the oesophagus.

Bile synthesis in rat models of inflammatory bowel diseases

BACKGROUND

A broad spectrum of hepatobiliary disorders are found in patients with inflammatory bowel diseases. The aim of the present work was to study interactions between gut and liver in experimental rat models of colitis and small bowel inflammation.

MATERIALS AND METHODS

Colitis was induced either by trinitrobenzene sulphonic acid or dextran sodium sulphate. Small-bowel inflammation was induced by indomethacin. Bile acid secretion, bile acid pool, and cholesterol 7-alpha hydroxylase were studied. Cholesterol 7-alpha hydroxylase protein expression was analysed in the microsomal liver fraction. As portal mediators released form the inflamed gut we measured lipopolysaccharide, tumour necrosis factor-alpha and interleukin-1beta in portal serum. The hepatic inflammatory response was evaluated by binding activity of nuclear factor-kappaB, activator protein-1 and alpha-2-macroglobulin.

RESULTS

Increased bile acid secretion, total bile acid content in gut and liver (bile acid pool size), and hepatic cholesterol 7-alpha hydroxylase protein and mRNA levels were found in the two colitis models associated with only a minor hepatic acute phase and cytokine response. In contrast, during indomethacin-induced small-bowel inflammation bile acid secretion, pool size, and cholesterol 7-alpha hydroxylase decreased in parallel to a strong hepatic cytokine and acute phase response.

CONCLUSIONS

Colitis without portal cytokine release and acute phase reaction shows an induction of bile acid secretion, pool size, and cholesterol 7-alpha hydroxylase. In contrast, intestinal inflammation after indomethacin treatment is associated with an acute phase response and a repression of bile acid synthesis.

[I/D polymorphism of angiotensin I converting enzyme gene and arterial hypertension in patients with type 2 diabetes mellitus]

Type 2 diabetes mellitus and arterial hypertension coexist very frequently. About 80% patients with type 2 diabetes suffer for hypertension, which is connected with higher morbidity and mortality from cardiovascular diseases. There are evidences that activation of the renin-angiotensin system (RAS), one of the most potent factors in blood pressure regulation, can decrease insulin sensitivity of tissues. As I/D polymorphism of angiotensin converting enzyme (ACE) gene can influence the activity of RAS, it may also influence both carbohydrate metabolism and blood pressure.

AIM OF THE STUDY

To assess the relationship between the I/D polymorphism of ACE gene and frequency of hypertension and values of blood pressure in type 2 diabetic patients.

MATERIAL AND METHODS

Examined group: 108 type 2 diabetic patients (38 women and 70 men), with mean duration of disease 9.07 +/- 6.68 years, mean age 59.98 +/- 9.10 years. We assessed following parameters: body mass index (BMI), waist/hip ratio (WHR), arterial blood pressure. Laboratory tests: concentration of the glucose, glycosylated hemoglobin (HbA1c), creatinine and urinary albumin excretion rate (UAER). Insulin resistance was calculated by the HOMA rate. I/D ACE gene polymorphism was evaluated by polymerase chain reaction (PCR).

RESULTS

DD genotype carriers had significant higher systolic and diastolic blood pressure (147.8 +/- 19.8 vs 138.2 +/- 16.5 mm Hg, p = 0.03; 89.2 +/- 9.6 vs 81.7 +/- 8.6 mm Hg p = 0.004; respectively) than II patients. Groups with II, ID and DD genotype were not different in age, BMI, WHR, duration of diabetes, the prevalence and duration of arterial hypertension, degree of metabolic control of diabetes and insulin resistance assessed by HOMA rate.

CONCLUSION

In type 2 diabetic patients the DD genotype of ACE gene is not connected with higher prevalence of hypertension, but it is associated with higher systolic and diastolic blood pressure.

[Relationship between I/D polymorphism of angiotensin I converting enzyme gene and microvascular complications in type 2 diabetic patients]

BACKGROUND

Type 2 diabetes mellitus is an increasing problem in developed countries. Microvascular diabetic complications can lead to worsening of the quality of life and lifespan shortening of diabetic patients. The renin-angiotensin system (RAS) seems to play an important role in microvascular blood flow. I/D polymorphism of angiotensin I converting enzyme (ACE) affecting activity of RAS may contribute to development of microvascular diabetic complications.

AIM

The aim of the study was to evaluate association between I/D polymorphism of ACE gene and presence of microangiopathic complications in type 2 diabetic patients.

MATERIAL AND METHODS

108 type 2 diabetic patients (70 men and 38 women), mean age 60.0 +/- 9.1 years with mean duration of diabetes 9.1 +/- 6.7 years were assessed for presence of microvascular complications (nephropathy, retinopathy, peripheral neuropathy). Subjects were examined for metabolic control of diabetes, lipid profile and degree of insulin resistance based on HOMA rate. I/-D ACE gene polymorphism was evaluated using polymerase chain reaction (PCR).

RESULTS

Diabetic nephropathy was diagnosed in 44 patients (42.7%), retinopathy in 34 patients (31.8%), and peripheral neuropathy in 58 patients (53.7%). Microvascular complications were found (at least one complication) in 83 patients (76.9%). Patients with microangiopathy and without microangiopathy were characterized by similar distribution of I/D ACE gene polymorphism. In carriers of DD ACE genotype blood pressure and HDL-cholesterol serum concentrations were higher than in patients with II polymorphism.

CONCLUSIONS

1. The ACE genotype is not associated with the presence of microvascular complications in type 2 diabetic patients. 2. In type 2 diabetic patients there is an association between DD genotype and higher blood pressure and serum HDL-cholesterol level.

Inhibition of phospholipase A2 activity by conjugated linoleic acids in human macrophages

The objective of this study was to assess the effect of conjugated linoleic acid isomers (CLAs) on the expression and activity of phospholipases A(2) (PLA(2)) in human macrophages. Macrophages were incubated with 30 microM cis-9, trans-11 and trans-10, cis-12 CLAs for 48 h. After incubation, the total activity of phospholipases as well as the expression of mRNA for cytosolic (cPLA(2)) and secretory (sPLA(2)) phospholipases and activity of sPLA(2) were measured. Both CLA isomers reduced the total activity of PLA(2) (by 30.2%, P < 0.01 for cis-9, trans-11 CLA and by 30%, P < 0.001 for trans-10, cis-12 CLA). Trans-10, cis-12 CLA isomer downregulated the expression of mRNA of sPLA(2) and decreased the enzymatic activity of this enzyme (by 23%, P = 0.02) in macrophages. Conjugated linoleic acid isomers can significantly reduce the activity of PLA(2) in macrophages and downregulate sPLA(2) expression. The consequence of this effect may be reduction of releasing the arachidonic acid (AA) from the cellular membranes of macrophages.

[Fulminant pancreatitis--internal point of view]

In acute pancreatitis pancreatic necrosis and involvement of different organ systems determine clinical course and severity. There is no method to predict the outcome of acute pancreatitis at the beginning of the disease. If there is evidence for severe pancreatitis, an immediate intensive care of all organ systems is needed, to avoid complications. Besides clinical signs, serum CRP is the most valuable parameter to define severity. According to present knowledge, a CT scan is only needed in sepsis or multiorgan failure. Non-invasive ventilation should be started early in case of hypoxia. Up to now, no general benefit was detected for antibiotic prophylaxis or enteral nutrition.

Nerve growth factor secretion in cultured enteric glia cells is modulated by proinflammatory cytokines

The enteric nervous system is composed of neurones and glial cells. These enteric glia cells (EGC) appear to be essential for the maintenance of gut homeostasis and mucosal integrity. Neurotrophin nerve growth factor (NGF) also plays an important role for the gut integrity by regulating sensory and inflammatory processes in the intestines. Here, we demonstrate EGCs as one source of NGF and show increased levels of NGF mRNA/protein and tropomyosin receptor kinase A (TrkA) mRNA in cultured EGCs upon stimulation with proinflammatory cytokines and lipopolysaccharides. NGF is continuously secreted from cultured EGCs and proinflammatory cytokines and lipopolysaccharides stimulate the secretion of this neurotrophin in a time- and dose- dependent manner, whereas interleukin-4 had no effect on NGF expression. Furthermore, NGF secretion was sustained for more than 12 h after withdrawal of the proinflammatory cytokines, suggesting the involvement of transcriptional and/or translational processes. Thus, the release of proinflammatory cytokines can increase NGF secretion by EGCs and leads to a higher expression of TrkA in EGCs. NGF, in turn, can increase visceral sensitivity and, on the other hand, appears to improve gut inflammation. Therefore, NGF secreting EGCs may play a key role in modulating visceral sensitivity and might be involved in inflammatory processes of the gut.

Insertion/deletion polymorphism of angiotensin I converting enzyme gene and left ventricular hypertrophy in patients with type 2 diabetes mellitus

INTRODUCTION

Left ventricular hypertrophy (LVH) is a well known risk factor of death from cardiovascular causes. Patients with type 2 diabetes mellitus are at particularly high risk of developing cardiovascular disease, which accounts for 80% of deaths in this group. Type 2 diabetes mellitus is probably related to increased left ventricular mass (LVM). Existing data show that the renin-angiotensin-aldosterone (RAA) system may play a role in the development of LVH. Since the I/D polymorphism of angiotensin-converting enzyme (ACE) gene influences the activity of RAA, it is likely that it could also have an impact on LVH.

AIM

To assess the relationship between I/D polymorphism of the ACE gene and the severity of LVH assessed by echocardiography (Echo) in patients with type 2 diabetes mellitus.

METHODS

The study group consisted of 103 patients (37 women and 66 men; mean age 60.1+/-9.1 years) suffering from type 2 diabetes mellitus with a mean duration of 9.0+/-6.5 years. BMI, waist-to-hip ratio (WHR), arterial blood pressure, LVM and LVM index (LVM indexed for body surface area [g/m(2)] or height raised to the power 2.7 [g/m(2.7)]) were evaluated. I/D polymorphism of the ACE gene was determined using polymerase chain reaction (PCR).

RESULTS

Distribution of I/D polymorphism of the ACE gene in the study group was as follows: genotype II--32.0%, ID--42.7%, DD--25.2% of patients. LVH was diagnosed in 43-71% of patients (depending on criteria used). Distribution of individual genotypes was similar in patients with and without LVH. Genotypes II, ID and DD were observed in 37.3%, 31.4% and 31.4% of patients without LVH (according to the Levy criteria) and in 26.9%, 53.9%, 19.2% in the LVH group, respectively. In persons with DD genotype, when compared to group II, significantly higher values of systolic and diastolic blood pressure were noted (147.7+/-20.2 vs 138.2+/-16.7 mmHg, p=0.03 and 89.4+/-9.7 vs 81.9+/-8.7 mmHg, p=0.004, respectively).

CONCLUSIONS

In patients with type 2 diabetes mellitus there is no relationship between I/D polymorphism of the ACE gene and LVH.