Heart failure in patients is associated with downregulation of mitochondrial quality control genes

BACKGROUND

Mitochondrial dysfunction is one of key factors causing heart failure. We performed a comprehensive analysis of expression of mitochondrial quality control (MQC) genes in heart failure.

METHODS

Myocardial samples were obtained from patients with ischemic and dilated cardiomyopathy in a terminal stage of heart failure and donors without heart disease. Using quantitative real-time PCR, we analysed a total of 45 MQC genes belonging to mitochondrial biogenesis, fusion-fission balance, mitochondrial unfolded protein response (UPRmt), translocase of the inner membrane (TIM) and mitophagy. Protein expression was analysed by ELISA and immunohistochemistry.

RESULTS

The following genes were downregulated in ischemic and dilated cardiomyopathy: COX1, NRF1, TFAM, SIRT1, MTOR, MFF, DNM1L, DDIT3, UBL5, HSPA9, HSPE1, YME1L, LONP1, SPG7, HTRA2, OMA1, TIMM23, TIMM17A, TIMM17B, TIMM44, PAM16, TIMM22, TIMM9, TIMM10, PINK1, PARK2, ROTH1, PARL, FUNDC1, BNIP3, BNIP3L, TPCN2, LAMP2, MAP1LC3A and BECN1. Moreover, MT-ATP8, MFN2, EIF2AK4 and ULK1 were downregulated in heart failure from dilated, but not ischemic cardiomyopathy. VDAC1 and JUN were only genes that exhibited significantly different expression between ischemic and dilated cardiomyopathy. Expression of PPARGC1, OPA1, JUN, CEBPB, EIF2A, HSPD1, TIMM50 and TPCN1 was not significantly different between control and any form of heart failure. TOMM20 and COX proteins were downregulated in ICM and DCM.

CONCLUSIONS

Heart failure in patients with ischemic and dilated cardiomyopathy is associated with downregulation of large number of UPRmt, mitophagy, TIM and fusion-fission balance genes. This indicates multiple defects in MQC and represents one of potential mechanisms underlying mitochondrial dysfunction in patients with heart failure.

Changes in Serum Lipid and Lipoprotein Levels in Postmenopausal Patients with Node-Positive Breast Cancer Treated with Tamoxifen

Tamoxifen has been used for a long time as an adjuvant hormonal treatment in breast cancer patients. We studied 62 newly diagnosed postmenopausal women, aged 50-79 years, with node-positive breast cancer and receiving adjuvant tamoxifen (20 mg per day). Total serum cholesterol, triglycerides, HDL-cholesterol, LDL-cholesterol, VLDL-cholesterol, apo AI, apo AII, apo B and Lp(a) were determined before the surgery and 3, 6, 9, 12 and 24 months after starting tamoxifen treatment. Tamoxifen significantly reduced total serum cholesterol (6.13+/-1.20 mmol/L vs 5.21+/-1.05 mmol/L) (P <0.01), LDL-cholesterol (3.72+/-0.70 mmol/L vs 2.93+/-0.51) (P <0.01) and Lp(a) (0.11+/-0.07 g/L vs 0.02+/-0.01 g/L) (P < 0.01). There were no changes in triglycerides or HDL-cholesterol serum levels during tamoxifen treatment. The results indicate that an additional beneficial effect of adjuvant tamoxifen therapy may be that it decreases cardiovascular risk in such patients.

Prevalence of asymptomatic chlamydial urethritis in military recruits in the Celje region, Slovenia

The aim of this research was to evaluate the prevalence of asymptomatic chlamydial urethritis in military recruits in the Celje region (population 300,000), Slovenia. A first-void urine specimen was tested for Chlamydia trachomatis using the polymerase chain reaction assay. The research was supported by a questionnaire to obtain information on sexual behaviour of the participants.

In the cross-sectional study from 1999 to 2001, 1272 asymptomatic recruits were included. None had received antibiotics in the previous two weeks. The mean age was 19.9 years. At the time of their first sexual experience the mean age was 16.6 years, whereas the age of their female sexual partners was 17.1 years. During their first sexual intercourse 77% of recruits used contraception (condom, diaphragm, contraceptive pill), most of those a condom (86%).

The prevalence of asymptomatic chlamydial urethritis was 2.6% (95% confidence interval: 1.7 to 3.5). The mean age of those infected was 19.8 years. At the time of their first sexual experience the mean age was 16.2 years, whereas the age of their female sexual partners was 16.9 years. During their first sexual intercourse 57% of infected subjects used protection, half of which was a condom. Those who never or only occasionally used condoms were at a greater risk of being infected with C. trachomatis (adjusted odds ratio 2.04).

Problems in the current psychiatry residency training program in Croatia: residents' perspective

The aim of this study is to evaluate the quality of the current residency training in psychiatry in Croatia using parameters of professional achievements of residents and their subjective evaluations of the residency training that is being offered. 66 residents from 15 Croatian psychiatric hospitals, clinics and wards in general hospitals fulfilled the questionnaire constructed to obtain information about the profile of psychiatry residents in Croatia, parameters of educational quality and evaluation of offered residency training as seen by residents. We interviewed 89% of all residents that had a trainee status in September and October 2006 in Croatia (66 out of 74). Study results indicate that Croatian psychiatry residents are derived from a pool of very good medical students and the majority is engaged in postgraduate studies and research activities and shows high interest in specific psychiatric fields such as psychotherapy and clinical psychiatry. Most of participants are only partially satisfied with the residency training that is being offered and feel that most problems reside from the lack of practical psychotherapy, the inefficiency of the mentorship system and the lack of funding resources. The results of this study revealed the major problems of psychiatry residents in Croatia. Following those results, we will perform the study that would include mentors and supervisors from different Croatian psychiatric centers. That could enable the development of specific interventions with aim to improve current residency training in Croatia.

Kidney ischaemia-reperfusion injury and polyribosome structure

BACKGROUND

Inhibition of protein synthesis and polyribosome disaggregation are the early events in cell injury provoked by various pathogenic mechanisms, including energy depletion. Polyribosome disaggregation might be expected to occur during ischaemia-reperfusion injury due to ischaemic energy depletion, but also due to detrimental effects of reactive oxygen species on various macromolecules and cellular structures.

METHODS

Mouse kidney ischaemia-reperfusion injury was provoked by temporary clamping of the renal artery. The polyribosome sedimentation pattern was analyzed by sucrose density centrifugation of kidney postmitochondrial supernatant.

RESULTS AND CONCLUSIONS

Ischaemia for 5 min in the mouse kidney provoked polyribosome disaggregation and an increase of monomer ribosome fraction which was augmented during 10-360 min of reperfusion. Recovery of polyribosome aggregates appeared between 6 and 24 h of reperfusion. Cycloheximide pretreatment prevented only polyribosome disaggregation caused by ischaemia and not that caused by reperfusion. This indicates different mechanisms of polyribosome disaggregation during ischaemia and reperfusion. It probably occurs in the former due to inhibition of initiation of translation, resulting in accumulation of unprogrammed monomer ribosomes, and in the latter due to the splitting of mRNA and breakdown of polyribosomes. Reperfusion did not increase ribonuclease activity in kidney cytosol, but increased the tissue concentration of malonaldehyde, indicating an augmentation in oxygen free radical generation. Possibly these may have caused a non-enzymatic breakdown of polyribosomes. However, pretreatment with allopurinol did not prevent polyribosome breakdown during ischaemia-reperfusion injury.

[Current use of bisphosphonates in clinical oncology]

Bisphosphonates represent nowadays a standard therapy of tumor induced hypercalcemia and are progressively more used in the treatment of tumor bone metastatic disease. Among several bisphosphonates, pamidronate is one of the most commonly used in clinical practice, so we also used it in succesful treatment of patients with breast cancer bone metastases. It has been shown that pamidronate reduces the frequency of hypercalcemia, bone pain and pathological fractures, although the mechanisms by which these effects are achieved are not completely clarified. Bisphosphonates are also important not only in treating patients with present metastases but also in prevention, or at least, delay of bone metastases onset. Recently, there are clinical trials examining the so called adjuvant therapy, that means the use of bisphosphonates in prevention of bone metastases in high risk breast cancer patients without distant metastases. In addition to breast cancer, multiple myeloma is another area of successful bisphosphonate application. In this paper we present some of the clinical results following the use of pamidronate in breast cancer- and hypernephroma-patients with hypercalcemia.

[Methemoglobinemia caused by accidental poisoning with metolachlor and metobromuron]

An 81-year-old man was admitted in the emergency department approximately four hours after accidental, ingestion of an unknown quantity of herbicide "Galex 500 EC". This product contains 25% of metolachlor and 25% of metobromuron dissolved in xylene. In spite of the fact that the combination of aniline and urea-substituted derivatives is widely used in agriculture as herbicide, there are very few data available about their harmful effects on humans. These agents appear to be mildly toxic, and rarely has a major systemic effect been reported after the poisoning. On admittance, our patient showed remarkable cyanosis and his methaemoglobin level was 38.4% of the total haemoglobin, rising next day to 46.2%. Only mild transient signs of hypoxic effects on central nervous system were observed and the laboratory findings indicated mild haemolysis. Methylene blue was applied intravenously in a dose of 1.5 mg/kg (10 ml, 1% solution) on the second day of admission. Administration of methylene blue was very effective and the patient was discharged from the hospital fully recovered.

[Hormonal therapy with aromatase inhibitor in advanced breast cancer]

We investigated the aminogluthetimide therapy effect on 30 postmenopausal women with advanced breast cancer previously treated with tamoxifen as a first-line hormonal treatment. Aminogluthetimide exhibits anticancer effect by inhibition of aromatase enzyme which plays a key role in the conversion of androgen to estrogen in peripheral adipose tissue. This pathway presents the main source of estrogen in postmenopausal women. Mean duration of the treatment was 14.3 months. Complete remission has been achieved in 10% of all patients, and partial remission in 16.6%. Mean duration of free intervals was 16.1 months in the group with ER+/PgR+ hormonal status, which is significantly longer compared to the ER+/PgR- and ER-/PgR+ groups where it was 11.8 months (p < 0.01). Aminogluthetimide treatment led to significant decrease in estradiol (E2) and dehydroepiandrosterone-sulphate (DHAS) levels in plasma. Thus, the effect of aminogluthetimide therapy as a second-line hormonal therapy has a benefit in the treatment of metastatic hormon-dependent breast cancer patients.